Using the principle of unbendable arm we progress to the traditional (at least in our school) method of learning to roll from a crouch position. Here we try to maintain the body's centre at a constant height above the mat and roll like a wheel across the mat thus avoiding collision and maintaining energy as we move.

Here's a diagram by Craig and text by Eri to give you an idea of what we mean (click to expand). There are lots of tips here, just focus on one or two at a time. of course the dojo is the place to use develop skills under the tuition of an instructor, try at home at your own risk!

Our basic rolling method very similar to what is shown here by Donovan Waite Sensei, His DVD's go on to develop to some very advanced ukemi

Basic Ukemi from Donovan Waite