I was lucky enough to paint from the live model for two nights in a row. Sometimes that is a great way to really start to see WHAT you are doing - right and wrong! I used watercolors both sessions on a very thick (200 lb) watercolor pad, which was new for me - up until now I have been using either Wallis paper or lighter watercolor pads. The 200 lb paper hardly warps at all!
Practice, practice practice :)