Dan and Erin Ries are two amazing instructors who are so skilled at teaching and break everything down into such detail that the moves become easy to learn. How they describe things really makes you comprehend the techniques.
In part two of the series, they focus on the arm in cross-collar choke. This is generally a hard move to pull off, but with their details, it increases your chances a ton! If you've been struggling with this choke, this is a must-watch.