Here's an awesome Open Guard Drill to improve your transitions and control. The Open Guard is one of the most difficult guards to master in BJJ
Here are some Push/Pull concepts that can help any BJJ student, especially if you are a beginner trying to build your Open Guard.
The Tripod Sweep is one of the most fundamental moves in BJJ. You can sweep your opponent from many different guards, using this same principle.
Professor Gustavo Gasperin teaches the main points of control of the Collar & Sleeve Guard, and how to set up submissions from there including triangle choke, omoplata, and a quick armbar.
Here is a quick video where I walk you through some basic concepts on how to play the Open Guard in a self-defense or street fight situation.