Keep it small

Try to keep the group to a manageable number so that everyone is able to contribute and schedules are easier to coordinate. A group of about 3-5 people is likely to be productive since it's big enough to benefit from the strengths of members yet still small enough to hold each other accountable.

Keep it short & regular

Short but regular weekly sessions are likely to be more effective than meeting last minute to cram -- especially for an economics class where cramming for an exam is far from optimal. Ideally, the group meets at the same time each week so that you don't have to worry about conflicting schedules every single time. 

Keep it focused

Online study groups are much likelier to be successful by assigning a moderator (or taking turns) to help keep things focused and organized. The moderator can set an agenda of topics and nudge the group away from tangents. Basically, it's as simple as having someone set goals for the session and reminding the group of the task at hand if things get sidetracked. 

Suggestions for moderator(s)

• Use deadlines as a guide

• Ask your peers what they would like to cover -- text them, call them, email them...whatever works

• Let everyone know what is planned for the next session so that they show up prepared

Working on practice problems is great but think beyond that. The group as a whole should also take time to identify key concepts in order to better understand them. 

Commit

With a little initiative members can be a great resource for each other. Hold each other accountable but also encourage each other. This should be a healthy, balanced exercise of give and take. 

Resist the urge to be distracted by email, social media, etc. Make it a pact for the success of the group.

Recommended Resource: How to Create an Online Study Group -- New England College