There are no real rules. I say practice the way you WANT to shoot. If you can do 0.5" groups @ 50 yards with a bipod and no rear bag and the guy beside you can do 3/8" groups with a Caldwell front rest and a rear shooting bag then you should still feel proud.
If I get my clock cleaned by someone using a Lead Sled with his rifle all strapped in, I don't really care, that's not my game. If I shoot 1.25" at 100 yard with my scope and a guy turns in a 2" group with iron sights, I'd be impressed.
At this point with my shooting I'm using a Caldwell front rest and a rear bag because I'm really trying my hardest to see how the gun shoots, not me. Once you know how accurately the gun will shoot, then you can see how well you can shoot, the way you feel shooting should be done.
That my philosophy, but like I said, there are no real rules.