I usually take apart electronics at my desk (one of my favorite hobbies). When I do, screws fall on the floor which is terribly annoying.
So, as an inventor, I'm not going to get off my chair and pick them up.
The parts I used are:
A neodymium magnet from a hard drive
One screw and a nut
An umbrella handle
And, tons of cable ties
Step 1: Selfie Monopod
I hate taking selfies so I didn't do this, But it is also possible to attach a phone bracket like this one, glue the magnet onto the bracket and attach the phone.
Be careful when putting a magnet near your phone screen!