Watch the Looks are Deceiving online guitar lesson by Brad Carlton from Chord Studies: Evolving Triads Vol. 1
Let's look at the voicings for this I - IV - V progression. You'll start with a second inversion A chord. Notice that although the shape resembles a D chord, it is derived from the C form of the CAGED system. Move your hand up one position and move your second finger over to the third string, and that gives you a first inversion D chord. Maintain the barre, slide down to 7th position and simply come down with the third and fourth fingers for the E. On the E make sure your thumb is in the middle of the neck so that your little finger doesn't mute the first string.