So now you have a glued together sprite that is all dry. Pick him up and remove the paper backing...there will probably be some glue back here but no worries, no one is going to see this side. Time to finish the piece. These steps are all optional...but I like to seal the piece, paint the back and mount a support on the back.
I like to put a bunch of coats of Clear Gloss Sealant on the pieces. It makes them look much better. Be sure to seal the edges too!
After sealing I turn the piece over and cut some strips of wood to make a support structure for the piece. Here you can see the simple pieces glued down to the back. These make the piece stronger and also make the piece pop off the wall a bit (which I think looks awesome).
I like to use a router to cut a groove in the bottom of a horizontal support...this is what I use to hang the piece on the wall (screw head slides into groove).
Then I paint the back black to finish it off and that's it! You now have a classy stained wood pixel piece!