From the experience I’ve gained, I thought I’d share some knowledge to the basics of horizontal play.
practice with different yoyos; some yoyos may be good at lateral tricks but bad a horizontals.
try practicing what you’ll do sideways normally; ex. practice yuuki slack normally and then try horizontally
KEEP THE YOYO MOVING; it doesn’t matter if you are messing up, you can always recover. But in order to do that, you have to ‘go in circles.’
twist the string over your wrist to shorten the string if it’s too long
let momentum drive the yoyo; don’t push your luck and try something you’re not sure if you can’t move your hands/arms fast enough. Let the yoyo glide.
as soon as the yoyo hits the string, start moving; don’t take time to decide what your next move will be. With horizontal tricks, there is no time.
MOVE YOUR UPPER BODY!!! A LOT!!!; it is absolutely necessary to follow the yoyo with your upper body. When you are starting horizontals, it is so much easier to ‘go where the yoyo is’ then it is to force the yoyo to the string with your arms.
be loose; don’t be as stiff as board. It may take time to actually get used to having your body flipflop around, but it is definitely the best way to learn.