Prioritize what you study. For example, don't focus on memory items and flows while still in Indoc. (a few guys in my class did, seriously... and the instructors even told us that the new QRH was about to come out). Something that may help in systems is to read over the material the night before you go over it in class. That way you know a little bit what they are going to talk about, and you can have questions ready.
Also, knowing basic turbine systems may help. The Saab engine is an axial-flow, free turbine engine. If you know the basic systems and generally how they work, you can spend less time trying to figure them out and focus more on things like the DECU, HMU, and AISBV.
And ditto on limiting the study groups. I didn't go to a single one because I felt that it would be more confusing with 20 people who didn't know what they were really talking about.
You will also hear about/have access to the question bank... DON'T simply memorize the questions and answers and think you'll fly through training. You'll pass the written tests, but God help you if you go into your oral not knowing how anything really works in the plane or when different lights will come on together (like, the Bleed Fault light and associated chime will come on whenever you close the bleeds, even if they close properly and immediately). I used the question bank more as a confirmation of my knowledge, not the foundation.
I'm sure I'll think of more later on.