Your legs jump with the bike. If you don't jump, you won't hop. No, I don't grip the pedals with my feet or anything like that (some recommend pointing feet down, I don't understand or do that). I think a better description would be to spring up as opposed to push back on pedals. Also note, it can take years to get good, don't be discouraged after a few attempts. I must've done 10,000 hops over the years. Commit aswell, put something infront of you (back pack, a coke can, a traffic cone), or like dbvaughndb usually says, hop 1 stair, then 2, then 3 stair... build your way up, that's what I used to do. If you really wanna commit, hop chains.... there is 0 room for error hopping chains. You make it or you near die. Lol. That's later tho. All the best.