Do you have access to a trampoline? That is a great teacher for tumbling. Learning to tuck while falling, in order to roll out onto your back. Most people stiff arm the ground and break wrists and arms. Or worse yet, hit their heads.
Or learning to hit the mat with your knees (pads) and elbows (pads) while lying out flat, instead of landing on your hands. Sliding out prone in a bowl or half pipe is so easy once you learn to fall to your pads!! Always keep your joints slightly bent so as to not lock up your elbows or knees, which can result in a break. While wearing shoes, you might even want to put all your pads on, and practice running and sliding across the bottom masonite of an indoor half pipe using all 4 knee and elbow pads.
Basic tumbling skills on the ground (like your front or back yard) will also help. Practice that as well, slowly building up speed, until you can do a tumble while running faster. Progression is key! Master it standing still before you try it faster and faster.
I'm so happy to hear that you are getting back into skating after your long hiatus. Good luck, and good rolling!!!
: I know the sideways falls are not ideal. but i know they do happen. more then once as this video shows! and i know i need to plan for them so to not break my arm. in those shown, they were rolled out but hit on the sides of arms and elbow. the arms were curved in like i was told was correct. in that way the forearm and wrist wont be broken. an outstretched hand would have ended badly in those falls. i cant expect I will always be able to hit my kneepads so i need to know how to land bad slams. if i cant survive a bad slam, i will have to hang up my sk8s. people think i should already but i know i can slam bad and land more safely so this wont happen again.
: : : love the video! More thanks from me because at 4:02 and 4:37 it confirms to me the proper way to fall sideways so I never break my arm again. I know I will be OK now!!
: : In Germany, we used to distinguish between two kinds of falls: Slams and Bails. Slams are uncontrolled, hard, injury-prone, painful. Bails are controlled, easy, injury-free and painless. I'm not sure if those words are used in the same way by Anglo-Saxons.
: : Obviously, you want to bail rather than slam. As everything else, this has to be practiced. It's easiest if you have someone around who is proficient in good bailing technique, because he can watch you and give corrective advice. In the beginning, inline magazines propagated six-point falling techniques which looked ridiculous to experiences skateboarders but where sufficient to prevent serious injuries. The technique just wasn't very elegant but an OK starting point. You would land on your toes, knees and palms and slide it out. When you got more confident, you could put your weight behind you and only slide on your toes and knees. On roller skates, there is a variant which skiers call telemarc-style (I'm not a skier, obviously). In this variant, you'd slide on only one knee, while still rolling on the other skate. Often you wouldn't slide it out but stand up again and push up the ramp again, thereby losing much less time.
: : In videos not every fall is a good role model. Often, there is a slam session included to show off the hard falls the skaters in the video have survived. You shouldn't try those at home.