Well with 15 votes, 40.5% the one most asked for even if just out of cruelty is the combination of pinch smooth and flatten! It definitely should be a challenge. ;D
I figure might be fun to see what everyone would like to see next from my brush experiment.
If you're not familiar with it, you can see the results of the Grab Brush here.
Looking forward to the challenge ;D
I just noticed the Smiley that I put after (I will hurt you) didn't show up, so just wanted to make clear that it was jokingly put, as i'm not even sure with all 3 of these tools if one could model a head.
ya I saw, it looks pretty good for first time and really there's no reason to restrict yourself from smoothing it helps keep the geometry from getting messy, is a modifier for all brushes, and doesn't add geometry