..of my middle finger of my left hand (my fretting) hand yesterday while being over caffeinated and trying to cut wire and change a track at the same time

. It's nothing too bad, but it's going to take at least two weeks for me to use it to play guitar again, so I figure, "fuck it- now's as good a time as ever to get my pinkie up to par with the rest of my digits..." Anyway, I can use my little finger for fretting things like barre chords and simple harmonics, but I really have no where near as much control over it as my other fingers, so I'm asking - Does anyone have any practice tips beside "practice, practice, PRACTICE" such as specific exercises for making pinkies a little less worthless in regard to playing guitar? Or, is that really all their is?
And, also on the subject of pinkie playing I was trying yesterday melodic runs with my three remaining fingers and after a few minutes of using my pinkie for things like bending and hammer-ons it would start to cramp up- any advice on avoiding that?
Thanks, all