In addition to the existing 'Dynamic Lighting' mode, I've made a couple more drawing tools. So far these include 'Perspective Grid', 'Skeleton Overlay' and 'Simplified Form'. These can be cycled through using the Q and E keys after selecting the statue that you wish to draw.
I've a couple other drawing modes/tools in mind such as a Silhouette View, Weight Distribution or maybe even an Action mode where sculptures in the middle of a dynamic action are animated completing the motion to give artists drawings a greater sense of dynamism... OK that last one sounds like a ton of work, I'll think about that again when everything else is done!
One drawing mode I do plan on adding for sure though is a 'Constructive Anatomy' mode. This would display useful anatomical notation painted individually onto each sculpture. This coupled with other modes like the Skeleton Overlay allows artists to view reference in real time as they draw.