[Stiglr]

All of those are different subjects.

For texturing, the TCE is a great, easy to use tool. You'll probably need to be able to use Photoshop, PaintShopPro or Gimp or some sort of advanced graphics program to create good textures (and creating those is an art unto itself!)

For detail and cleanup, that comes from experience: your first models will always be kind of a mess, because you're learning. But, as you progress, you'll make fewer and fewer "mistakes", you'll create objects that are "cleaner" using less polys, etc. And you'll learn how to hunt down extraneous vertices, double sided polys that don't need to be double sided, etc.