detailing pencil sketches on the computer

Question

Forgive me for i'm not especially talented with graphic design. I was trying to make some icons for my mobile app which more or less is following a chalkboard theme. I thought that it would be easiest for me to do some pencil sketches on paper and import those into photoshop and play with the blending options.

The result is actually quite fine for my tastes but i want some of these to be colored a bit and pop-out of the board and sorta rest on top of it, show a little dimension. My issue is that these are what i'm working with with blending options normal:

Something like that above kinda is hard for me. I don't know whether to color right in because the resulting colors are always skewed. I don't know if i can just cut out the outline, because there's more black inside as well as outside. If i'm not being clear, i hope that this final picture will show what i'm attempting.

Answer 1

The easiest method is to scan the drawing.
Place it on it's own layer.
Add an additional layer below the scan.
Set the scan layer to "Multiply".
Now just color on whatever layers you need below the scan. You can use 1 layer for all the colors you want or one color per layer, however is easiest for you.