Actually I mostly just search for tuts & try to play with a few things. Here is what I do with these:
1) Put your pic together
2) Run a "artistic - poster edges filter" play around with it
3) Run a "artistic - cutout filter" again play till you like it
4) Now duplicate that layer....work on the new (top) layer
5) Now do a "artistic - film grain filter" ...mostly grain = 4 & Intensity = 2 works
6) Run "pixelate - color halftone" filter ...radius 4 works best normally
7) Turn the "opacity" of this top layer down till you like it
You're done!!!
Hope it works for you