I did the full time course at OATS and found that after studying all day in the classroom, all I could manage was three one hour sessions broken by a 1/4 hour break after each hour. I worked from 5 p.m. until 8.45 p.m., then kicked back, relaxed , ate and had 2 drinks each night.
That way I found worked. I passed all the Tech and Nav exams first time. It drew a nice line under a days study to be able to wind down in front of the tv.
Good luck, and dont over do it!!