What helped me was to practice chord change exercises I learned on Justinguitar.com. For example I would switch from an A to a G, back and forth for a minute as fast as I could go and note how many chords changes I did CLEANLY with no missed or muted notes. You would then switch to another random 2 chords like A to an E, D to a C, F to D, etc,etc. I did this 15min a day and it really helped me getting my hand and fingers in the correct position for each chord.