I have the opportunity to sight in a couple of dozen rifles every few months so I have it down pretty well. We shoot alot of pds at some long distances and rifles have to be on or you waste a ton of ammo.
I usually start by checking the bore and the scope to make sure they are at least in the same general time zone. Then I will shootone shot at 25 yds. from a decent shooting bench with bags for support. If I plan to shoot the rifle with a bipod, I sight it in with one, other wise bags. Make whatever corrections and shoot again at 100 yds., make whatever corrections and then I'll do a bit of testing at much longer ranges to get a feel for what the gun will do out to say 300-400 yds.
Never have used a gun vise or sled, just bags and bipods.