One thing I like to do is go back over previous work and try to improve it. One such example was my Admiral Daala.
My first attempt was using ewok Leia's head and torso with Adi Gallia's arms and legs. I went a little overboard on the chest.
For my second attempt, I used an imperial officer for the body and Zam Wessel for the head. I had to sculpt on long red hair and chest.
It's definately an improvement I think. Anyway, I'd love to see how others have improved their previous work. Please post pictures of all of your attempts, what you changed and what you've learned.