You're certainly right about the unpredictable results you can get from curlers. I found using them takes a fair bit of trial and error before I got reasonably adapt at it.
It's important to pay attention to the angle of the wind at the scalp. Wind straight out and your hair will stick straight out. Wind at a low angle and your hair will lie low. Also, how much hair you put on the individual roller is a factor. If you fill your head with rollers, the set will probably be pretty tight.
The longer you leave the curlers in, tighter they seem to come out for me. With hot rollers, you shouldn't need them in very long for the desired look. Once the rollers cool, you're probably done-- 15 minutes or so. Remember the curl will relax over the first couple of hours after a set, so if it's too tight, you might wait awhile before spraying or anything. Sometimes I'll mist it with water before combing relax it a bit, too.
Mostly, it just takes practice, though. BTW, I think you look great in the pic.
Lyric