Illustrated Maps - Paper textures on top or below?

[TimetoDraw]

Hello all

I've stretched myself to creating an illustrated map for the lite challenge this month though now I've run into an issue with how to proceed. (I'm a photoshop user).

Do you usually lay down paper textures first, and begin to paint on a multiply layer on top?

Or do you paint your map first. Then add paper and other textures on top towards the end, setting it to overlay or multiply to varying degrees.

My painting skills are ok, but looking at the very talented illustrated maps on here has me wondering about the best way to handle the textures. (Previously I have painted characters with no textures. Or regional maps with textures and less paint. Joining to two techniques has stumped me for now with how best to do it.)

For reference, here is the piece in question.