I had, (and sometimes still do) have the same problems. What helped me was to learn to the the Spock greeting (from the ORIGINAL Star Trek for you youngins) (like a peace sign with your middle and ring finger, then change to the reverse of that. (ring and middle together, pinky and index spread apart)
You can practice this anywhere, in traffic, class or where ever you are)

You have to teach your fingers to move independently. Concentrate...you can do it....