First, I'm going to tell it that I want a minimum of 4 branches and a maximum of 5 branches per section, and then I'm going to disperse them a little bit. So, click the Limb button under branch level next and then click the Size property. I've already changed the defaults here. I shortened the limb's section length except toward the ends of the limbs, I decreased the branch length from 100 to 80, but I left the diameter alone. Click generate and check the results.
Chances are good that the limbs are too short.
So, go ahead, experiment a little. I ended up setting the length back toward 100 and re-dragging the spline down a little so that the limbs would have smooth transition in length. After you make your changes, click generate. The spinner in Angle to Parent defaults to 60, sometimes you'll want a smaller angle such as 30. But the most important thing to know about this window is that a little drag goes a long way.