I moved some of the ideas below into the list and added my own. -ChadMiller
One thing you should definitely do in order not to teach Go is to criticize every move your student makes, without also taking time to praise the good moves.
And note: even if a move isn't actually good per se by your own standards, it may actually be an attempt by your student to put into practice the principles you yourself have been trying to teach - and it may be tons better than the move he would have made before he heard your instruction. So, the best way not to teach Go in this case would be to harshly criticize the move in question anyway, since you see about ten times more clearly than your student and know exactly what's wrong with the move he made. Do this regardless of whether or not the move actually showed that your student is learning.
Here's another one: make sure never to ask your student what his thought process or intention was in making whatever bad move he made. Just assume you know exactly what he was thinking - or better yet, refrain from caring at all what he was thinking. Just criticize the move. If you suspect the move was made for reasons having to do with whole-board strategy, then make sure to criticize it on tactical grounds. Conversely, if it was a tactical move, criticize it on strategic grounds instead. Under no circumstances should you address the relationship between these two areas of consideration. This will greatly confuse your student, and you will be moving rapidly closer to your goal of not teaching Go.
A favourite method of not teaching go to someone: start explaining the rules, ko, life&death, territory, sente, gote, joseki, shape, influence, shinogi, the carpenter's square, and the subtle differences between rules to your student before even playing the first move. I've seen this in real life (well, maybe I exaggerated a bit). Scary.
Dieter: What you mean is that you should not tell someone what he should not do ?
No, I meant explain only the very basics (e.g. play stones on the intersections and not in the squares, stones don't move afterwards) and then start playing immediately. What good is it for a beginner to know about the carpenter's square, when he has not even placed one single stone on the board yet?
HansWalthaus: But make very sure you have a booklet containing the rules when teaching it quickly in a pub. New players who are focusing on 'game' instead of 'learn' tend to moan and complain when introduced to Ko or life&death in the middle of a game. Always have some paper back-up. It prevents a lot of howlers like: 'Cheater!!! Cheater!!!!'
As in anything else, a little encouragement goes a long way. The teacher could say 'I can see the merit in that move' and state what merit there is, and then perhaps say '... but this may be a better one, can you see why?' -- Wysi
Another not I recently witnessed is this one: I welcomed a beginner and taught him the game with some atari-go games and one fast real game on 9x9. Then our lowest ranked player came in and I was happy to team them up. I left the table to have them enjoy Go. Unfortunately, another player came in, who sat down and kibitzed, explained, kibitzed, explained, and thoroughly analyzed each move. The newcomer got more and more puzzled, left the club with the idea that Go was indeed very very complicated and he never returned. By all means, don't overexplain ! -- Dieter
(moved from Teaching go to newcomers / Discussion)
Chris Hayashida: Don't start by playing a handicap game against them. It doesn't make the game any more fair. There also isn't a need to prove that you can beat them. In my opinion, it's better to teach simply, and let them learn quickly. On an empty board, the game is less confusing. Giving 5 stones on a 9x9 make it look like the student has the entire board, only to be left with none of it at the end of the game. As a side effect, the student will also see White play more "normally," which will help develop their understanding of the flow of play.
Toorima?: It's best to start out with a explanation on the Shusaku kosumi and with the many josekis that they will see in the future, And if you have free time go into the Taisha Joseki. 9x9 wont give the full feel of the game so 19x19 needs to be used to start them out.
Alex Weldon: Perhaps a good way not to teach go would be to rely solely on Pavlovian conditioning for improvement, rather than explanation. Rather than explaining why a given move is bad, simply hit the student with a stick after every move, with the amount of force used varying with the badness of the move. After the student has improved to the point where not all moves are bad, good moves can be rewarded with food pellets. (ChessWhiz: LOL!!)
Jasonred : I consider you kind people in Sensei's as my teachers. Thanks. Though sometimes, I get the feeling that if I could rise 5 stones in strength, I would gladly request Pavlovian training... yeouch...
Chipuni: That would be a popular combination in San Francisco: Go and S&M!
TJ: I find it most useful to move into not teaching go by immediately following the first nine-stone handicap game they've won against me by a session of explaining how White made some bad moves, allowing black to win. The deeper one goes into how better moves by white would have led to complications from which black could never have had even one live group on the board, the better. The student, feeling over-whelmed by your superiority, will soon move on to another (no doubt less imposing and more level-appropriate) teacher, leaving you to contemplate your navel in peace.
mAsterdam I removed
from the list. I actually tried it. After that they want to reduce the handicap to get into it. It works. It should be on the other page. Any other experiences?
DougRidgway: Probably there's literature in the education community as to the appropriate level of positive feedback for most rapid learning. I'd guess that it's maturity dependent and larger than the 50% from quote-unquote correctly handicapped games. I'm probably most comfortable when I'm winning two out of three, or so: like 70%. That would be somewhat overhandicapped. From my experience with small children, I'd guess that something north of 95% success is appropriate there. They do not have the tools to deal with negativity. I find it kind of odd that the tradition is to underhandicap, such that the stronger player wins more than half. This makes sense if it's a competition that the stronger player ought to win, but not to maximize learning for the weaker player.
Proposed: Start with capture go. Once they get the hang of that they'll take months to realize that that it isn't go they are playing - if ever.
Dieter: We had that debate. You can't dismiss it with just a fancy statement. If you never go beyond capture go, the problem indeed exists. The problem is even bigger when you start by explaining territory and never move beyond. I've seen people instructed with territory play a game that looks much less like Go than people instructed with the capture game. A good teacher goes from 1-stone capture to more stone capture and then to the real stuff at the proper moment. Kids who are forced to walk before they can crawl will fall on the behind and cry helplessly.
mAsterdam: The rule of capture should be explained, of course. Kids who learn music by only reading scores will never learn how to create it.
ChadMiller: Atari Go is a religous argument. How about the qualification, "decide whether your student is bright enough to learn two different games"?
Dieter: I'm not so much angry because someone advocates against the capture game - I am fully aware that good ways of teaching go without it exist - but because the (above stated) arguments pro are not answered. The comparison with Pente is flawed. There is no way you can play pente and gradually change the rules until you can say: you know, you're playing Go now. In fact, I am quite convinced Go has originated from putting down stones and capturing them (Chinese rules) and that delimiting territory is a mere, albeit beautiful, consequence.
And I repeat: unlearning making territory is harder than unlearning capturing stones. Well, I'm not angry at all, of course. Case sensitive, maybe #:-7
Dieter: I created territory pitfall. The whole idea that Go is primarily about territory is flawed, in my opinion. BTW, you can have more territory than me, as long as the sum of my territory and captured stones is bigger than yours.
jfc: I definitely agree with you -- area rules are far superior to territory rules when teaching a newbie!
 yoyoma I think it would be less confusing if we said "don't do this" and "don't do that" rather than rely on the page title being "how not to teach go" and expecting people to reverse every sentence's meaning based on that page title.
ilan: Here is my last experience with a "sensei". Back when I was 11K, a 3D "friend" of mine played me some 7x7 games. In the first game, I won by 24.5 points (he did not score a single point!), and his comment after the game was: "You made some mistakes." I should note that he said this after he himself had just played on a neutral point, allowing me to make a seki. This is the game http://files.gokgs.com/games/2003/6/4/cyril-ilanpi.sgf
In the second and final game, I was winning again and he started telling me to move faster since it was annoying to wait for me to move. This was at a critical moment, and I made the only wrong move under pressure. He then admitted that he had done this intentionally to provoke a mistake. Here is the game: http://files.gokgs.com/games/2003/6/4/cyril-ilanpi-2.sgf
Robert Pauli: The page should explain how not to do it, it shouldn't criticize this bad way directly. For instance, it shouldn't be
Stay on the 9-line board too long. Though it's great for teaching the basics of play, fortunately it's also good for boring your students after the 30th game. Even after they're ready to move to the 13-line, insist on the 9-line board.
Stay on the 9-line board very long. 30th games might be enough to bore them to death. As soon they're ready to move to the 13-line, insist on the 9-line board.
"Start off with a 19x19 Board. Give them 20 stones handicap, but don't explain anything but the raw basics. Proceed to capture all their stones. Gloat."
This seems awfully similar to items already in the list.
I find little that's unhelpful in the first two sentences. I think under-explaining is far better at keeping the players attention than over-explaining, and 20 stones is not bad either.
The last two:
"Capture their stones." It will give a wrong impression of the game's prupose, so perhaps it will sufficiently confuse them.
"Gloat." Already covered by another item.
I think I'll try to refine this item later, unless the author fixes it first.