I think study GROUPS are a waste of time (often), though I think getting a study partner can be helpful.
For first year, a study partner and I drafted an outline for each class together, based on our briefs and class notes. We'd develop a skeleton outline from the table of contents, then discuss each case--coming to a consensus on a clear simple rule of law (if possible). This process would take one to two days for each substantive class.
Then, we'd read a practice exam or two to make certain we could spot the issues.
The above works if you find someone with a personality that complements yours and a similar level of brainpower. You MAY be able to add a third, though a fourth or a fifth would really muck up the process. The two of us ended the first year with similar, respectable GPAs.
The above is also good b/c one need not get super-intense about studying for exams until about 10 days before the first one to pull it off.