A friend of mine asked me if I could make a tripod mount for his Lumia 1020 phone, and I found one here on Thingiverse. However, when I printed it, the clip was too large and didn't hold the phone, plus it was really hard to screw the tripod into the hole.
So I created this design. I've tested it on both a Makerbot Replicator 2 (the yellow one) and a MendelMax 2.0 printer (the black part).
This design uses a brass threaded insert, which will last much longer than threads cut into the PLA plastic.
If you're printing in PLA, like I did, you'll need to have very good cooling to ensure the printed threads are of high quality. Also, you'll need a threaded insert. I purchased a bag of E-Z LOK 400-4 threaded inserts, which have a 1/4-20 internal thread. Here is the link to the Amazon page with more details: http://www.amazon.com/gp/product/B00207NF6W/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1
To insert the thread, you'll need either a very large screw driver. Or something like the coin shown in the photo (I used a U.S. dime, which was just the right size). Screw the insert into the threaded hole until it seats firmly.