We got the kid an inexpensive cell phone for Christmas. Printable cell phone cases are a dime a dozen on 3d printable sites, but pretty much only for iPhones and Galaxies, so if I want to print a case, I have to design it myself.
It was harder than I expected. Finding the basic dimensions was easy, getting the precise locations of all the buttons and ports and such a bit more difficult (it involved wrangling a rigid ruler held up against slightly curved surfaces), and getting Sketchup to play along was remarkably difficult.
I started by drawing a basic rectangle. My plan was to poke some holes in it, use the offset tool to expand the area by the desired thickness of the sides, and the push/pull tool to raise the base and edges by suitable heights.
The biggest problem is that, once I made the desired "cuts" in the base, using the push/pull tool would raise or lower the face and leave walls outlining the cut-out for the camera and the name, but didn't extrude it into a solid. I had to copy the base, raise the existing copy to the desired thickness, and then paste a copy of it back at the original height to close up the solid. I also couldn't figure out how to cut holes through the raised sides, so the cuts go all the way up. Here's what I ended up with:
The printing took forever, but it worked fairly well:
If/when I do this again, I'll probably take a different approach. I'll probably do something similar with the base, but for the sides, I'll design slabs of the appropriate dimensions for each side, poke holes as appropriate, and rotate them 90 degrees to use as sides.
Oh, and ideally I'd use Ninjaflex or some similar flexible plastic rather than relatively brittle PLA.