Is your scale the kind that uses impedance to measure body fat %, etc.? Just wondered, because with those your feet are supposed to be dry, not damp, when you use it. Not sure whether that affects the weight reading, though.
Choose a time and stick with it.
First thing in the morning after you pee and before you shower sounds like a good time. Get on the scale ONCE at that time and record what it says.
Otherwise you'll be hopping on and off the scale all the time trying to make it "work"--and that's silly.
If you think it's really off, get a new scale.