So when I'm having trouble gaining speed in certain parts of the infinite maps I use a technique which I call "Bunny Hopping". Basically, whenever you open your glider there is a small speed boost in whichever way you are facing. So by facing slightly downward when you jump and very quickly opening and unopening your glider, you'll gain a lot of speed especially if you can stack the it.

Also if your having trouble front flipping instead of tilting make sure your not holding down W or front arrow key. Try jumping then hold down W don't combine the two. also i personally think its much easier to do in first person view since you just have to watch the tips of your skis or ski

In short, jump (space), tap or hold W for a short time, the press shift twice.

let me know if it works for y'all or if you have any other questions!

it may take a couple tries but i promise once you get the hang of it, it makes the game so much cooler.