Lie them flat on their side, and peel off the felt while you're at it; drink tea a while and leave honey drippings on the nosetip.
Jk, although it is true: placing them uncentered or even barely touching another square drives them mad! (Lots of OCD in chess). In the park the knights go to the intersection of, I kid you not, four squares, and later it's all like, "nah man, that was here."
I was told recently that one (or more) GM places the knights facing the king and keep them facing in that direction throughout the game so that they always know which is the king knight and which is the queen knight. Personally, I like to face them forward toward the enemy position.
I saw a video of Magnus Carlsen doing this, so I guess there is some merit to it. Does anyone know what benefits may be provided by knowing which knight is which?
Supposedly, this helps in the analysis process. I can't imagine how it would help at my playing level, but to a GM it must make some difference.
I was playing a game the other day and my opponent turned the Knight sideways and because it had a long frilly mane I could barely see the piece behind it!
Just pick up the knight and spin it over the square you want to place it on, it will stop where it wants to...
I place my knights backwards to confuse my opponents - they may see me retreating, but they won't see me coming.