After taking some photographic detour I got back on track with my drawing exercises (Drawing Lab by Carla Sonheim). Most of them are easy to do and more important: fun!!
Drawing Lab 9: Wrong-handed portaits and Drawing Lab 11: Cheater Blinds were both kind of BlindContourDrawing exercises. Did those alot, but I never succeed doing the drawing without looking at my paper. Lucky me: cheating was allowed;)