About detail, I believe a certain professional mapper once said the devil is in the details. Whoever it was, he's right. With increasing production times, planning becomes more and more important if you want to avoid wasting your time on models, textures or map pieces that finally will never get used. It may take some time to get a good workflow, but if you want to continue mapping, spend some time on getting an efficient workflow. It's well worth it.
About detail again, small thing's aren't necessarily details. Large things can be details, on the other hand, just as small things can be. The shape of a large building can be a nice detail that works better than the texture applyment on the light pole next to it - the building with it's interesting shape draws much more attention than a light pole, doesn't it?
In other words: put in detail where it is likely to be noticed. Area's that are seen a lot should have a higher detail level than area's or surfaces you hardly ever see. You don't waste polygons in a pit-dark corridor, right? And ceilings are often much less detailed, since the player doesn't often get too close to it (and most of the time he'll spend his time looking at the walls and floors more than looking at the ceiling, so...).
i knew you guys would just point me to some wierd direction 