Well if its overnight I would be doubly sure he/she 1) Can't speak, 2) Can't get out, 3) Won't be too sore. Of course it would depend on the situation really, but either way I have lots of time to tie up the victim very securely.
If its part of a game of some sort then I'd tie up the person securely but in a position that is not too uncomfortable so that when he/she wakes up then the person won't be sore or cramped. Then I'd do a spread eagle tie. If not, then I'd do a hogtie with extra rope bindings for the elbows, thighs, knees, ankles. If I don't have a bed to use in the former case then I'd tie him hands front and ankles tied together and arms tied with the body.
I would use a scarf gag in either case with several layers with a knotted cleave gag as a base.