Get one of those pop socket things, either one that sticks on a case or attaches to a case. The Otter Box above is nice, I have one that fits over my Apple silicone case. I like that I can adjust level of pop socket so I can stand my phone up vertically at different angles, but they super similar outside of that.
That's helped me tremendously for single-hand usage, and I'm also using my non-dominant hand a lot because of some recurring arm pain on my dominant side.