I see maaaaddddd people bashing, hating, smacking kufi, joking on, and in general destroying other peoples bikes. SO; to avoid dirty looks from fellow forum members lets make a list of things to generally remember when altering/creating your own fixed gear:

Brakes - you need to stop
Foot retention - toe clips/straps, or clipless, etc
Seat Height vs. Bar Height - The seat probably shouldn't be higher then the bars/stem
Riser bars with a neg. degree stem

I'm at work and have school soon so I'm out of time, add!