I think I'm just a bit of a grubby boy :|
I try get a shower or bath once every two days... But sometimes I'm lazy and leave it longer - I always have a wash in the sink if this happens though (arn't I lovely :P )
Teeth? I'm really bad T__T Once a day in the morning if I remember (which is mosst of the time)
I don't shave, just give it a trim every now and again.
I alsways wear a fresh t-shirt/shirt (unless maybe its the weekend and I'm being lazy and not going out) but trousers can last for weeks!