Personally, the script I use for a quicksentry is
bind F11 "destroy 2 0; wait 10; build 2 0"
Blows up your sentry, then preps another for placement. Won't actually place until you click, which I find is good for more precision placement. Also only works on servers which allow the wait command (good thing OCR does).
Oh, also
bind F11 "+attack;wait 6;lastinv"
for the spy knife. It replays the draw animation every time you stab someone. Increases the cooldown slightly, but I just can't stop.