This'll probably be long but I'm going to attempt to tell you our method without using pictures... wish me luck
This if for a more judo-esque breakfall. If your dojo is using the newer soft breakfall style this probably won't help you.
1) Start lying on the ground in whatever position your sensei wants you to land the breakfall in. Make sure it is corrected by a senior student or your sensei because everything builds off this landing position being correct.
2) Lift and lower the slapping hand/arm and the lower leg. Practice slapping the mat with the hand at the same moment the lower leg contacts the ground. Exhale as you slap. Have your postition checked each time. Repeat 10-15 times then switch to the other side.
3) Once you get the hang of step #2 start alternating right and left sides with each slap. You'll be rolling from side to side. Exhale as you slap. Have a senior watch to make sure your finishing position is correct. Repeat 10-15 per side.
4) Once your hitting your finishing position correctly on a consistent basis start adding some height. Do this by kicking your legs up then landing on your side. This is tough without pictures but it is a little like a URL="http://http://www.youtube.com/watch?v=vDlQ6ExGHgk"]"kip up"[/url] but you're just trying to get your legs and eventully hips up off the floor so you can let them tip over to the side and practice your landings. Think like you're trying to put both feet flat on the ceiling, tip to one side and land in your Sensei's approved position. As long as your landing position is correct keep kicking up higher until you're getting all the way up onto your shoulders. Make sure to exhale as you slap and have a senior watch you.
5) Now we start the rolling and landing portion. Get in position for a right side kneeling roll. SLOWLY bring your right knee all the way to the floor, leaving your left leg stretched out behind you. SLOWLY bring your right shoulder and right side of your head to the floor and reach deep under your body with your right arm like you're reaching for your left foot. Keeping your left leg straight bring it up and over your body and land in the correct position. Exhale on the landing and have a senior watch to make sure your landings are correct. And remember this isn't rolling practice it's practicing your landing from a rolling motion. Repeat 10-15 times then switch sides.
6) Get in position for a right side standing roll. Do your roll as normal EXCEPT keep your back leg straight and land in correct breakfall position. As always exhale on the landing and have a senior watch your form. Repeat 10-15 times and switch sides.
7) Get a senior student and grab each others wrist right hand to right hand. Explain to your senior that they are to be your support, they're NOT throwing you. Have them stand 90 degress to your left, you right arm should be crossed in front of you. Now, start tipping forward over your right leg and lifting your left leg to keep a straight line from the top of your head to your left heel. Continue going deeper and deeper until you start to reach your disbalance point. Repeat on the other side.
8) Same position as #7. Once you AND your senior know where your disbalance point is tip forward three times like step #7. On the third tip forward you need to be sure to be all the way to your disbalance point. At this point your senior will help guide you over the disbalance point and you will go over your arm like a child flipping over a bar on the playground, and land in the position you've been practicing all this time
This all sounds like it would take weeks but in truth I've run people with no previous experience through this in less than one class time. Some of the stages can be shortened or even skipped depending on previous experience or just how fast somebody picks up on it.
I hope it helps, be safe.