mental preparation befor the game

Yes, green tea and apples is much better than coffe and cigarettes.

I also like browni's hints.

Green tea is great, because it has very little caffeine, but contains the calming and cognition improving effects from theanine. Any substance that has a strong effect should be avoided.

I also like browni's advice, but my own experience is in chemicals, and though I'm not a great chess player, I do know that pretty much all drugs are bad for chess performance.

#12, is it through experience? ;)

The only drug i was on when playing chess was weed (i dont take any other drugs including alcohol and cigarettes, excluding coffeine). The experience was:

a) I played enormous creative (i checked the games after).
b) sometimes i did incredible blunders.
c) no matter how or how much i lost, i was never angry, not the slightest bit.

especially c) stunned me. The weed completely blocks any disturbing influence of the ego.

It fits into the logic of this world that it is an illegal drug.

My preferred preparation is to browse my porn collection and then not actually play chess.

"#12, is it through experience? ;)"

It is. I don't drink much green tea anymore, but I used to enjoy it daily. Besides the theanine and low caffeine levels, the polyphenols and antioxidants are good as well as the subtle umami flavor.

Awesomer, I've had similar experiences. It also seems to simplify the game, and the squares that are controlled/attacked are very clear to see, yet still so easy to miss something big.

Thanks for all your answers!
I will try to engage in soul-searching instead of just starting a game in the future.
#14 indeed, i should also stop playing stoned.. incredible blunders but fun.