One of my best sellers are the Button Up Phone Cases I make. I can't make them fast enough to list before they're sold. I've experimented over the years and love the button closure opposed to the velcro tape, snap buttons,and ribbon strap. The button closures give me an excuse to use up the buttons in my collection and gives more of a cleaner and professional look.
I always try to coordinate the outer fabric with the inner one to give it a more cohesive look rather than just randomly choosing two pieces, which would make it much easier but just not as purty!
And, not only can they be used for your phone, they can double as your point and shoot camera case too.
Here are a few others that I've made: