You can go virtual reality, which is expensive and only allows you to see what the camera sees. However you leave yourself open to crashing into obstructions you can't see.
This is what I have done, and it works like a champ. Go to a hobby shop and get you some 0.030" styrene sheet. Cut it to make a shroud to go all the way around your phone. When you cut it out, make sure you tabs that will fit under your phone so you can attach it to your phone. I sprayed it flat black on the inside to cut any reflections. I left it unpainted on the outside since the controller of my Potensic Dreamer is white, so it matches. I have a separate 5G phone that I use just for my drone so my hood is permanently mounted. However, you can use strong packing tape and attach it to your phone when needed. If you make the sides 3" deep or so, you should still be able to reach your phone to control your drone if you like that. This will now block out the sun considerably and allow you to see your phone much better.
