how do you pick your spot for a set-up. walking through the woods, just driving along and spotting, topo maps (google earth).

When it's hot, maybe try a water spot or a trail to a water spot. If you have a hot trail that you're aware of then try it there.
Just gotta move it around until you start getting pictures. I'd leave it at least a week in one spot before moving it but that's just me.
I haven't gotten any deer pics on my new cam I put out two weeks ago but I'm getting foxes and yotes so I'm leavin it for now.

Spotting, walking trails, topos. Whatever works. Depends on what you want to get pics of?