Work with Others
I am not a big fan of study groups. The reason why is every study group I've been in has either been to flirt with girls or out of desperation because I hadn't prepared for an upcoming test. The problem was that most everyone else was there for the same thing, and I accomplished nothing.
What I have become a fan of is a testing group. Here's how it works: Gather a maximum of five test-takers who can meet every week. Each of you will create and bring 20 exam-like questions that deal with only two to three objectives to each meeting. Work your way through each of the questions as a group, using any reference materials or the technology being tested to prove or disprove answers.
Another angle on working with others that I've had mixed success with is having members of your group take turns delivering a thirty-minute lesson on a particular objective. This can reinforce your understanding of an issue, and create a sense of responsibility to know the information thoroughly prior to delivery.
In your lab, it can be helpful (and less lonely) to invite a partner to work with you through different exercises on each objective. I wouldn't recommend more than one partner, though, because too many folks have a tendency to screw around rather than work on a specific objective.