Alright I decided to stop what I was writing and add a lighting part. I see many sigs on this forum with good brushing, blending, and smudging but no good light source. Well now it's added.
I will also today be writing the clipping mask part.
And I might have Yippiyo help me out with this tutorial. If you haven't seen his latest PDN sigs here are some:
So he, if he accepts my offer, will be a huge addition to the guide.