Everyone has different criteria needed to be placed on I call "The priority list"
A priority list is a group of people you hold near and dear to your heart or would stop everything you're doing to give them your time. For me, to be on my priority list, I have to be on your priority list. If you do any of the following, it's a quick way to be removed from my priority list.
Being removed doesn't mean we're no longer friends. That would be extreme. It means that I'll treat you like someone I see at Dunkin' Donuts every morning. I say "Hello" engage in small talk and keep it moving.
Granted that you are a decent person, please head the following warnings.
If your friend spills their heart out about their lives but won't listen to your life stories, you're not important enough to them and you don't need them in your priority list.
If your friend holds too many secrets that cripple trust between you two, sneak them off your priority list.
If your friend consistently leaves you behind when you planned to do things as a team, leave them off your priority list.
If your friend consistently hangs up in the middle of your sentence, shut them out of your priority list.