British Go Journal No. 14.  June 1971. Page 5.
Every master player has his own peculiar habits and idiosyncrasies that appear while playing major tournament games. Here are some of the weird ones.
Hosai Fujisawa is a large man who appears to be sloppy until you see him play. However at the board he still likes to relax and sits happily with his shirt-tails hanging out. His thinking is so deep that he keeps on meditating, even talking to himself, while visiting the toilet.
Sakata is more nervous, preferring to give up his lunch so that he can sit through the break studying the game. When concentrating he unconsciously takes off his socks and sits barefooted. He gets into a squatting position and during the last seconds of byo-yomi exclaims maitta (Ive had it) as he must play his yose stone, as if invoking some religious ritual.
Rin Kaiho is still young so he doesnt display so many peculiarities and we have to be content with his pulling his knee up under his chin when under pressure.
It is said that Go Seigen prays to the ancient Chinese gods with every game whether he loses or not. However, how true this is I dont know.
The most famous player for his tournament style is Kitani Minoru. Of course he has now retired due to a weak heart but, in the old days, he would bring seven articles to aid his game all wrapped up in a carrying cloth (furoshiki). He needed 1) a pair of walnuts, which old Japanese click together in the left hand for relaxation; 2) a pot of honey, which he could lick for nourishment; 3) a nyoibo, a Buddhist priests staff to hit his shoulders with and to hold in order to calm his mind; 4) eyedrops; 5) special plasters and liquids for dabbing on his back and shoulders to cool his muscles; 6) tissue paper which he often shredded to pieces while playing; and 7) a special cup for his tea. Everything was arrayed about him in a circle before he could devote himself to the game.
Why dont you try some of these techniques in your own tournament games? However, I dont guarantee that theyll help you play like Kitani!