Find a downhill bit on the grass so you don't have to work to keep your speed up. I practice in the parking lot for manuals, it's actually easier on the race track in a few spots (like the one in my video), but I need to get better at it.

x games

You initiate a wheelie (or manual) by shifting your weight back and cranking down on the pedals. The pedaling force pushes the bike forward under you by driving the wheel ; while shifting your weight back rapidly shifts the center of gravity, causing the bike to rotate. You aren’t really pulling with your arms as much as hanging from them.

Same goes for the (arguably more useful) bunny-hop. You don’t really pull up on the bike, you bounce your weight up, and drag the bike along with you

gearing is everything

Yeah, I once borrowed mtb from my son in law kids and went in low gear up a little hill on grass and almost fell backwards without any pulling on bars. I had no intention to do any wheelie or stepping out LOL

If I should practice it, I'd definitely find some grassy place, the softer the better, also use platform pedals.