One of the ideas brought up by one of my players was that they wished there were drag and drop area of effect templates, for their spells, so we could stop drawing them all the time. I think it's a great idea, expanding on that, I think a menu in the side bar would suffice. You choose your template (sphere, cube, cone, etc) and size in click menus, and the program creates a template to drag onto the board. I think giving the dm control over all of them, but limiting player control to their own would be best.