This is an evening hack to replace the tube and rubber band holding my phone to a microphone stand so I have both hands to type when on video calls. It is really useful and you should consider building one as well.
First download the files from Thingiverse and 3D print the base. The STL file will be good for most microphone stands, but the OpenSCAD file is included if you need to tweak the settings for yours.
Laser cut the holder.
Use a [very] hot air gun, reflow, or heated wire to soften the holder's fingers and bend them round some wood. Remember to leave enough room for the phone, a phone case, the heads of the screws, and a little space to insert and remove the phone.