Most of my study time is a little weird. For A&P I and Micro, I study for 2-3 hours just before a lecture/lab exam. The rest of the time, I am careful NEVER to miss a lecture, and to make the most of my lab time. Usually, since I pay very close attention to lecture, I do well.
In Algebra, I have to put in an hour or two every day working problems and such. Then I review all formulas and units just before a test. Time consuming, but I only go to class about half the time.
As for my Web Development class, I work in five-hour increments, which is usually two units at a time, every two weeks. Assignments and exams are open and administered on the internet, so I can work at my own pace. That professor isn't a huge stickler for attendance, so I usually don't go.
(As a sidenote, of the two classes I attend less than perfectly, I did make sure to familiarize myself with the professors' policies on that sort of thing. You can usually tell - or, at the least, ask - whether subperfect attendance will bother/offend them. In those cases, they really don't care if anyone comes or not. I wouldn't slack on going unless I knew that for certain.
It's just rude, I think.)