When teaching golf to my students, I always suggest to place the ball at the following areas:
Full shots means you are swinging the club to full capacity.
1. Play the ball in front of your heel with your Driver, Woods or Long Irons #1, 2, 3, 4 when using a Tee.
2. Play the ball slightly back of left heel with your Middle Irons #5, 6, 7, 8.
3. Play the ball middle of stance with your Short Irons #9, PW, SW.