Here are some informative tutorials on how to sew binding on when the piece has different angles. One of my class instructors recommended them for our quilting projects. I have used these techniques on corner bindings. It is an easy method to follow.
This one is for outside corners.
https://www.youtube.com/watch?v=Vci9-li3aYU
Inside Corners here.
https://quiltwithmarcibaker.com/binding-inside-angles/
Enjoy!