Okay, I will try to help as much as I can.
- Jensen’s GT trick- If you could bring up the video of him doing it that would be great, but here is what I believe he is doing from what you said.
First, you should know how to do a trapeze green triangle. If not look it up.
Anyways, second you should know a trapeze and bro (the foundation to the trapeze green triangle) is almost exactly like a split bottom mount minus the fact that the loop around your throw-hand index is on a different sides of the wrap on you non-throw-hand index.
Next, go like you are going into a split bottom mount, but don’t go over your throw-hand index finger. Instead, go over your throw hand wrist and land on the string closest to your throw hand side. Have the loop on your wrist drop. Yay, you are in a GT. Now, just do a braintwister. Dismount to your throw-hand side. Sorry if I misunderstood.
Follow- Now, I can’t do follow, so here is a tutorial and video showing different variations of follow.
Sorry I couldn’t find many, and I can’t do the trick. But, for the part where you hit the loop with your hand, practice it with jade whip. When the loop comes up, push it back down with your non-throw-hand.
PM the person you are talking about.
Here are some from J. Lev. or Jeremy Levine. Check out YoYoExpert Tutorials on youtube. There are some good tricks on it. The videos shown here are from that account.
Hope this helped.