I started playing Bluegrass banjo 42 years ago.I started playing Rock & Blues on an electric guitar 16 month ago.I'm 59 yeaes old now.Both insturments gave me the same problem,I could not get my finger to form good sounding chords.I got good results using this method .Whenever I watched TV. read a book or just relaxing on a chair. I place my fingers making a chord on the guitar and held them in that poaition. An hour or so later my finger are stuck in that position.This is the fastes way to get muscle memory with little effert.Try it you'll like it, It works.