Step 1: Materials
A phone case that fits your phone (preferably hard plastic)
Wood veneer of your choice (I got mine off ebay for $12 here) (you'll probably want a few in case you mess up)
Glue (I used regular School glue but I highly recommend against using it, instead use super glue or something similar) juttep1 also suggested using spray adhesive, to ensure an even coating.
And a couple of basic tools
Step 2: Prepping the Stencil
This step is pretty straightforward. Just trace around the case onto a piece of paper and then cut out the paper. Then trace around the paper "stencil" on the veneer.
Step 3: Cutting the Veneer
Now you need to cut the veneer into the shape that is stenciled on it. You can use scissors or some other kind of tool that might be better. I used scissors, but if you have a better way, then please comment about your way because I feel like there could be a better solution.
Step 4: Gluing the Veneer to the Case
Now add some glue to the case and spread it out evenly. I used regular School glue at first, but I don't recommend using that instead I would use super glue or some better solution. Then place down the veneer onto the case and weigh it down for a while. I put several makeshift "weights" onto my veneer to keep it down. Once the glue has dried, or is close to dry, you should be good to move forward to the next step.
Step 5: Cleaning Up the Edges
Now you need clean up the excess edges on the veneer. I just sanded down the edges with sandpaper, and made them more flush with the actual case. I hand sanded it, but I would have used a dremel if I'd had it on hand, unfortunately I didn't, so I had to hand sand it. I would recommend using a dremel for this part though.
Step 6: Cleaning Up the Edges: Part 2
Now you need to fix any contours that you might still have, on the moto x (1st gen) case, there is a little dip near the top of the case. I used a razor blade to cut that part out and then sand out down to make it flush with the case.
Step 7: Sanding the Veneer (optional)
If you want, you can and down the top of the veneer to make it smoother and more comfortable, but this is optional.
Step 8: Staining: Part 1
Now, to make the wood look better, I stained the veneer. I used dark wood stain, and applied it with a rag that I dipped in the stain and rubbed onto the veneer.
Step 9: Cutting Out the Camera, Speaker, and Mic Holes
You are obviously going to need to cut out your holes for the camera, mic, etc., I used any tool that I had on hand, I used a drill with an appropriate sized drill bit for the mic, then a razor blade for the camera and speaker holes, I then sanded down the edges, which made all of the new cuts clean and even.
Step 10: Staining: Part 2
Now, I applied another coat of stain. I did this because all of the new cuts and sanding, brought more unstained wood, so I stained it again to make it look better.
Step 11: Finished
Now you are done! Enjoy your new customized phone case. Here are a couple pictures of mine. The dummy phone used in the photos was 3d printed using flexbuild3d.com. You can see my ible about ordering a 3d print from flexbuild here.
Step 12: Final Thoughts and What I Would Do Differently
Also, feel free to vote for this in any contests that it is in and feel free to ask any questions or comments in the comments section.