Step 1: Purchase and Disassemble a $1 Selfie Stick
Dollar Tree sells these for, guess what, a buck. This particular model has a head which attaches with a 1/4-20 thread bolt just like any tripod mount. Just unscrew the head but hold onto the stick.
Step 2: Mount Onto Tripod
Just screw it down. For an added bonus, plug the small cord into your headphone jack for a remote shutter release. Assembled, the collapsed selfie stick even makes a serviceable handheld.