I personally try to stay in the stand as long as humanly possible. I take some trail mix or something to snack on, maybe a sandwich. I also bring something to drink in small plastic bottles. I agree with FL/GA, find something to pass the time in the stand if possible. Too often, I've had the "bug" to get down, for one reason or another, and that's when I spook deer. It also helps that I know the approximate time deer should be heading through my area. This keeps me focused and interested in staying put.