Do NOT take a shower before bed. At least for me, showers are morning things, I can't lay down and sleep afterward, I have to get dressed and DO something, anything. If I try to go to bed after taking a shower all I do is toss and turn and stare at the dark ceiling, sleep is not gonna happen.
If I'm stinky, sticky or sweaty, a damp wash cloth with soap or some rubbing alcohol fixes that so that I can still sleep. I brush my teeth before bed, and if I wake up in the middle of the night with "xactly mouth" I'll brush again.