RE: How to not jump deer?
The deer you have "jumped" knew you were there, knew you were coming and just hoped you'd go right on by. But they got a little nervous and headed off.
I would say 90% of the people I've seen "stalking" move along WAY TOO FAST. I don't know how slow you're going but it's got to be slow.
I don't look for deer. I look for pieces of deer. A little patch of brown. A little patch of white. An ear. An antler. A nose. An eye. Any slight movement or sound gets me to stick in that place twice as long.