I use multiple layers. Put a new layer on, pick out the areas I want to colour, and then use the fill tool. If I want to use several different textures on one dress then I just fill the first new layer with a flat colour, this gives you a guide, and you can then use susequent layers, just picking out the areas you want. I have found that the easiest way to do this is to use the magic wand tool to select the background, and then hit invert in the selection drop down box. After that you can just click on each shape with the wand, and fill that area with the chosen texture. BTW it is sometimes better to extend the selected area by one or two pixels before filling to make sure you don't get any visible, unwanted seams on the final product. Don't know if this is the recommended way, but I find it easiest.

The greatest part of wisdom is learning to develop  the ineffable genius of extracting the "neither here nor there" out of any situation...."