Hmmm
For me, since my hair is relaxed and touches my shoulder, I have to use bigger rollers, because I like the doobie style. If you are looking for very curly hairstyle, that you can use smaller rollers.
There is no trick. All you do is(while your hair is wet), make sure it's smooth enough so when it goes around teh roller, it will dry, smoothly. The reason why rollersetting for me is easier is because I have teh covers for the rollers, I don't use pins. When you are using hair pins; place the hair on top of the roller and roll the hair over roller. When you get to the scalp, use a large hair pin and slide the pin beneath the roller and next to the scalp. I don't know if this helps. Next time I will try to get some pics for you...