Like tilt mentioned up-thread, it would really help if you could upload some of your work so we can see what's going on...
there is a lot of knowledge to draw on here, but trying to visualize the problems you are describing can be a bit difficult. This is mostly because there is never really any one single correct way to fix a given problem, it really comes down to preferred techniques in the end. And please don't be shy about uploading the WIPs...that's what this part of the is for