As far as choosing a particular spot, it's according to what you mean. Are you referring to what type of body of water to fish or what area of a body of water to fish. Personally, I like a place that's more secluded and "off the beaten path". If fishing in general, I prefer cover/structure.....
Clear water (versus muddy), vegetation and cover, and depth. If the water is real shallow, it will likely not hold many big fish. No cover in the form of vegetation, wood, etc is not good. Muddy water usually indicates the previous two (not deep, and nothing to filter sediment).
Having said that, there's always the mud hole that produces 8lb bass, you can never be sure until you fish it.
When I fish a lake for the first time or a lake I havent been on in a long time, I think back to similar days on similar water and try to duplicate something I did there. For example if I know I fished a lake with similar features under similar conditions at the same time of year throwing a spinnerbait around wood on windblown clay banks that will be the first thing I would try. If that didnt work I would think again about similar conditions on other lakes and try something else. Sooner or later I will find something that will give me a clue of what to do.
Thanks pgarick, glad to be here. This is one of the best forums I've been on (though I have rarely posted on any of them).
All good suggestions, by the way. Whenever I end up in some new place, the conditions (be it cover, structure, current, clarity, etc.) are always different. I was just curious what the rest of you thought was the most important thing to look for. Personally, I like to fish anywhere with structure. Submerged trees, stumps, rocks, drops, etc. But you guys pointed out some other good things to look for.