Here are some methods that can be effective for studying go. Please feel free to add to them, but preferably focus on the means of study rather than study paths. That is, a study technique is how you study, while a study path refers to what, specifically, you study (e.g., professional games, life and death problems, tesujis).
- Flashcards Making cards showing a particular technique, for instance a joseki or a killing shape. On the back of the card make notes on how this technique is best to be used (for instance, it's often good to choose a pincer when there's a hoshi stone in the adjacent corner to support the pincer stone). Not only do flashcards make it easy to learn and revise ideas, but the act of making them helps to get the material into one's head. You may also use a Spaced Repetition System(SRS), which is a computer software that allows you to simplify the process of creating cards and make it more efficient. You may use Anki for the purpose.
- Computer Libraries use a Palm Pilot to keep notes on any new ideas or tactics that interest you. It's easy to make notes and to adapt them or add to them. It's also easy to revise them. You can use a desktop computer for the same purpose.
- Interactive Reading Do you regard books as holy relics that must be handled with care and the greatest respect? Then you're probably not getting the most out of them. Scribble notes in them, highlight important text, fold pages, correct errors and make additions. Your books won't look pretty, but it will help to remember what they say because you get very involved with them!
- Lists To emphasize certain issues you can prepare lists and keep them nearby while I'm playing. For example,"1. Light 2. Positional judgment 3. Watch aji" close to hand. See also compass. See Playing Check List
- Random Testing Do you think you know the Large Avalanche joseki well enough to play it in an important game? Then why not test yourself before it comes to the crunch. A way of making sure things are staying in your head is to see periodically whether you can still remember the critical lines of such and such a joseki or tesuji line, choosing it at random. It can be sobering to get halfway through playing out a sharp variation only to find one is not certain whether the next move is at A, B or where?! If you test yourself regularly, you'll probably identify those ideas and lines that you really have most trouble with, and will be able to put things right quickly.
- Use a Ready Reckoner to learn the values of common moves and formations.
- Practice Reading Lines of Play One way to develop reading skills is to set up a situation on a goban or one of the Go Editing Programs such as CGoban2 that supports variations. Work out as many branches as you like. Restore the situation and then read out the variations in your mind. A good one to start with here is to lay out a ladder and apparent ladder breaker and to see if you can work out whether or not the ladder works? This would be Kageyama-style study!
- A way of playing. Each time there is a new decision to make, evaluate the position, look for exactly 3 moves that serve the objective, read out about 5 moves deep, considering only the most natural sequences that follow it and evaluate each sequence as soon as it dies out locally. Choose the move with the best resulting sequence. This looks like what we all do always. You know it is not.
- Another way of playing. Repeat the previous and speak out loud your analysis before playing the move.
- Repetition If you want to learn something, go over it over and again. Revise it again and again. Eventually you will reach the point where the very notion of forgetting the material seems absurd.
- Write a Book Not as daft an idea as it may sound: play through professional games and then make notes in an MS Word file of various techniques that interest you. Gradually, you'll be building up your own small dictionary of suji that won't be found elsewhere in English literature. Another way to use this technique is simply to write about aspects of the game, trying to explain them clearly. You will find that you naturally do research to back up your ideas and that your thoughts acquire greater clarity through being shaped into coherent prose.
- Teach When you teach another player, you are not only doing him a favour: you are teaching yourself too. By explaining the basic concepts to your friend you are also revising the foundations of your own understanding. Also, as with writing, having to frame your thoughts as comprehensible sentences for the benefit of your friend helps you to get a better grip on those thoughts.
- Force Feeding Basically, choose something to study, such as Life and Death problems, then do a lot of it and repeatedly. (And I mean a lot and repeatedly, like until your brain hurts.) The idea is that the sheer intensity of the learning experience will make the material stick. Force feeding, in the sense of extended repetition, might be useful if there's a particular habit that you need to pick up or change. Apparently it takes repetition over 21 days to change a mental habit (or, to create a new one). For instance, suppose you want to break the habit of answering my opponent's every move: you could pin a note by your computer saying "look for tenuki opportunities" and make yourself look at that while playing on the Internet. If this idea is correct, then after 21 days, your brain should have become programmed to search for chances to tenuki, and the bad old habit of responding all the time should be history.
- Chewing Gum No kidding. Apparently, the act of chewing (it doesn't have to be gum – peanuts will do just as well – though they are more fattening) causes the body to behave as though one is about to take a meal. The heartbeat increases, and with it the supply of insulin and oxygen to the brain. These effects assist reasoning and memory.
- Change Counting If you keep a bucket of pocket change, grab a handful of change, dump it on a table, spread it out so you can see all the coins, then count the total without touching it. 
- Learn from Every Game An efficient way to improve is to simply learn something from every game. Every game is different and there has not been one yet (nor is there likely ever to be one) in which you have played every move correctly. As the game progresses, keep tabs on the few (maybe one to three) situations that you want to study later. Often it is a joseki (or set of joseki stemming from a certain play). Other times it is a direction of play issue or something else altogether. Regardless, learning this way has one benefit: you learn things that are relevant and that come up in actual play. Going over games after playing them makes it easier to review in this way. But, just remembering the situations for a day or two and hitting the books (or SL) later works nearly as well.
- Make Every Game Count  Would a professional athlete (or go player) not train this way, doing wacky, random exercises (or playing wacky moves) for the hell of it? Certainly not. That may be one of the differences between pros and amateurs. But it is a difference that can be eliminated (while others cannot).
- Teach Yourself Go
- Memorize the first 50 moves
Tamsin: I have experimented with checklists, but I think they have their limitations. Go is too big a game to reduce to a handful of maxims. On the other hand, if there are certain bad habits you want to eradicate or indeed good habits you wish to acquire, then check lists can be a useful aid. For example, if you feel that you play the "obvious", "impulsive" move too often, then you might add an item to a list requiring you to find another plausible move once you have identified the one you are likely to play.
FFLaguna: I find that when you have to count something unordered, like a bunch of change lying in a semi-flat pile, or the fishsticks that you just put on the pan, or whatever, it's fun to just count them without rearranging them. You have to remember which ones you have and have not counted, as such. ^.^
Zarlan: I've read that people who play First-Person-Shooters tend to have a better ability to know the amount of objects they see, without having to count them. If this confuses you, then think about this: If you see, for example, three stones, you don't have to count them, do you? You instantly know the amount anyway.
Counting unordered thing, change and such methods might be just as good or even far better, but not nearly as much fun ;)
wdst20: I found this very useful. In addition I would like to make a mention that this helped me studying for some courses at University. There are additional things to add like breating and meditation. The way the japanese pro's sit is similar to a meditation technique. Taking a few seconds of the game, then returning to it can help you identify things you missed whilst you stared at the board for a good x minutes.
I found out this greatly helped simply doing 8). An opponent with whom I tried this out, continuously forgot to think and just played. Then I would ask him what his analysis was and he'd say "Huh ? What analysis. Oh yeah, I keep forgetting about that."
 Supermarket counting
Go on! Say I'm crazy. But what I do to improve my counting is I keep track of the accurate total cost of what I'm buying at the supermarket. And when I get to the cashier, I can check if my calculations were correct, and if I don't get screwed BTW. In France, we have two advantages for this technique:
- We suffered from a currency conversion back in 2002 from francs to euros, so the prices have become quite random with regards to the amount of cents (almost no round numbers),
- The tax is included in the displayed price so there's nothing to add at the end.
More, if you can remember what the price of each product was, you can even check on the cash receipt. Pretty interesting exercise.
 I've also improved a lot lately by not wasting time playing games in a non-serious frame of mind. I don't play silly, experimental games anymore. I do not play moves for which I don't know or can't read out the likely continuation. That is, I do not initiate joseki I don't know. I don't play the Taisha just for the drama of it. I play it if it makes sense and I know the continuation.
I do try moves I've not played before if I think they are appropriate and I can back that up with some reading. In this sense, the game is still experimental. But, I don't just slap down my first stone on the 7-7 point (or some such) just to be different. The reason is that, by games end, I will have no idea if that move was good or bad...it was just wacky. I find wacky for wacky-ness sake to be a waste of time when trying to improve.