It is often a good idea to wait until your move is decided before you take a stone from the bowl. There are two main reasons for this:
Another reason to do this:
-- TakeNGive (10k)
A variation on this is to hold an object, say a squeeze ball, in your hand while thinking about the move. That way, you restrain the impulse to reach out and play the first move that comes to mind.
- Tamsin Jones
Scartol: One time, during a very close and tense match, I stood up and put the bowl on the next table, where I couldn't reach them.
It's also a bad habit since the chance of dropping a stone onto the board increases from zero to something. :)
- Xrillo 5k
Haha, good point. :D
This applies to online play as well. Many awful mistakes on Internet chess and Go servers have taught me never to place my hand on the mouse until I've decided on a move. When I fail to follow that rule, I immediately begin to rush my moves.
The mouse exists to be clicked. That's all it does. As long as you have your hand on it that's exactly what you'll do - click, not think.
-- SirLyric