For the A I was taught this trick and it works very nicely and you can transition to other chords very easily. Put your first finger on the G string, your middle finger on the D string and your ring finger on the B string.They all fit much better that way and to me it is easier to play that chord like this. I was taught this years ago by a guitar teacher I had back then. He used to play with Dusty Drake and the Drifters.