It's just a personal thing, but I really don't like roll out skills. Many people find them just as safe as any other skill, but I just don't like them.. never did, don't think I ever will.
My suggestion for development, put a spring board in front of a porta-pit, and do fronts that you land upright. Easy. Put on another 8" mat, same. Should still be easy.
From there, move the spring-board in front of a spotting block turned on its side, so, roughly a front onto mats 2' or so above the ground. Behind the spotting block, but a porta-pit. Do a front onto the spotting block (or mats), punch dive roll into the porta-pit. You should land with your hands at your side, leaning forward a bit, and lift (your arms) them as you punch. This should significantly slow your rotation, and you need to feel that. In my opinion, ideally you should land on the spotting block in a "hollow" position with your hands at your side, leaning slightly forward.
From there.. it kinda depends on your comfort level. You should never land head first into a pit, so I don't suggest throwing them into a pit... though you could stack some resi's up in the pit and throw them onto that... otherwise, you just take out the spotting block and your front off the spring board should be high enough to do a 3/4 into the porta-pit, or try one on the tumble track into a porta-pit.
This is a potentially dangerous skill. Take it slow, and practice it often.. using a firmer 8" mat to land into would be better than a soft one, as the softer 8" mat would absorb more rotation and put pressure on your back in places you wouldn't want pressure.
ideally (in my opinion) you should be capable of doing a front and "standing up" in air about 2' off the ground before you go for the 3/4. Tossing a few doubles into the pit or off a tumble track would do you a world of good as well to develop the air sense you're looking for (and, I think, safer).