Especially on bikes with a certain amount of vibrations (those from Milwaukee for example 
) almost all stiff mounts tend to wear out after some time with an increasing risk of breaking material.
I prefer this simple but effective smartphone grip. It can be attached easily and is flexible enough to fit even thicker bars or risers. This grip also quite effectively prevents the smartphone from vibrations. There are also versions avaible to fix the smartphone in a horizontal position.
On the right side of the smartphone grip you can see this pen-loop which holds a small touchscreen pen. I used some tape and shrinking tubes to make a thinner part in the middle of the pen, so that it’s fixed securely. Useful if you haven’t touchscreen capable gloves (of course only while standing 
).
