Some people consider H-E-double hockey sticks to be a swear word.
Practice is the biggest aspect, but I have been practicing on and off for the last 13 years, and I never really got it, but watching John Higby effortlessly throw them with both hands for 3 days, something just clicked.
What I found out, the most important part of looping is in the first throw. The angle you throw it at, and how it flips over at your hand are key to consistent loops. It is different for everyone, but should be similar. Once I get back from MOYO, I plan on shooting video from the throwers view point, to see if I can’t help anyone else out there. I don’t think i have seen a video like it before.
My angle when the yoyo is at the end of the string is skewed as such: take the perfectly straight yoyo held out in front of you, now tilt the yoyo to the right at about 1 o’clock position. Now pull the left side of the yoyo towards you about the same amount that was tilted to the right. On my sunset trajectory, I can no longer see straight through the gap, and the left side of the yoyo is always looking at me kind of sideways, like he wants to punch me in the face.
I will try to get that video shot either at MOYO, or after when I get home.
Oh, one last thing. The yoyo does matter. I am not saying you can’t loop with anything, I am saying that you may need to do something different depending on the yoyo used. My method does not work on my Bumblebees, but does on my wood axle proyos, when they are behaving.