Watch the Dropping Down online guitar lesson by Brad Carlton from Chord Studies: Beginner Chords Vol. 2
In many of the previous examples you had to have your thumb in the back of the neck to facilitate having your fingers upright. In this example you want your thumb to hang relaxed so that way when you play your G chord it will be easy for you to dead the fifth string. Then all you have to do is come down with your first and second fingers to grab the Gadd9add#4. This progression isn't terribly hard, so why not try experimenting with some new rhythms?