Also use the factor of thirds   that is divide you your seen in 1/3 sections and making your main subjects set on one of the 2 lines divideing up the full render.  Always have somthing that will guide the eye to the main point if inderest leading in then out.  In photography you try and get rid of shadows but in art it is the shadown that meke your work come alive.  Hopes this helps and yes! do try not to cut you subjects feet off, they will need them to walk when they are done poseing for the day...