A while ago I practiced static hops, but never very seriously. I only started practicing hops intensely a couple of weeks ago. I quickly went from only being able to do a couple static to being able up hop in circles and make small rolling hops. I can jump some sidewalk cracks, but I’m far from jumping even a curb.
This has all been on my 29er, but I’m hoping to get a KH19 to help speed things along.
Jeez I’m jealous and that at your age 
When you hop sideways, do you hop continuously or do you only hop the moment you lose balance? Using the uni like pogostick I can do easily and turn around, but focusing my jumps to go somewhere is a whole different story. When you hop 40cm, do you keep the saddle in front of you?
Btw, when you hop, do you just keep your feet on the pedals or also on the cranks close to the hub? I maybe making it too difficult for myself by only standing on the pedals and when hanging forwards or backwards too much, the wheel rolls away a bit and I’m close to a face-plant.
And I’m jealous of Terry Peterson who is able to do this with a 36er:
Basically when I am hopping for keeping balance (I can’t idle) I don’t need to hop like a pogostick, I can hop when I lose balance and only then, it is less tiring. But at the beginning I was hopping like a crazy.
Also when the purpose is only to keep balance I can hop with my body instead of the rebound of my tire, so what really hops is my body, my legs play the role of a spring that absorbs the landing, so the unicycle barely moves upward.
When it is about using the rebound of the tire to hop high I put myself a little bit away from the obstacle, let say about 60cm if I want to jump over 40cm high, then I do a side hop landing at about 10-20cm from the wire and I push hard on the tire.
As soon as the tire bounces off I try to pull the seat toward my crotch and in the same time I let my knee flex so that my feet don’t struggle against the pedals rise.
I have never done that before cause I didn’t have the balls to jump on something that is 40cm high, but it’s ok to jump over a simple wire, especially if I increase progressively the height of the wire.
In the past I have trained to hop holding the seat in front, but for the same reason I never dared to jump this way higher than what I was able to jump with the seat under the crotch.
I mainly used “seat in front” hops to do one to two feet drops, or to climb on and off stairs or curbs.
Last week end I also managed to jump over the 40cm high wire without using the side rebound, just with the spring effect of my knees, like in the video of terry, it was less easy but I did it at least once.
The saddle of my trial 19er is not set as low as it should be for a trial purpose, it’s most set like a muni mode, only about 1 inch lower than my G26 (I am speaking about the distance between the top of the seat and the top of the pedal when it is in its lowest position :6h00), so I could jump over a higher wire with the same effort if I set the seat even lower but my goal is to transpose my abilities to the G26 for muni purpose.
I don’t think I’ll be able to jump the same height with the loud geared 26er, but if you can move mountains you can move molehills, so I’ll be happy with a 20-30cm wire jump.
When I hop I don’t set my feet close to the hub, it is just on the pedals.
On my bigger wheels (which includes the G26) I use 21mm to 27mm pedal extenders because it’s more comfortable for me.
What I recommend you is to try side hops (gaps) before trying to jump over something.
try to hop 10 cm to the left, 10 cm to the right, and when you are comfortable with this distance, increase it progressively.
When you are able to jump 50cm-100cm to the right and to the left, you are already jumping over a certain height without noticing it.
Try it with a 19er and with a very low seat.
good luck 
Cool thanks for the advice. My smallest uni is a 20" freestyle, but it is just as light and easy to jump with.
Now rain, please stop falling, so I can go out and jump/hop 
I’ve seen the extreme side hops that UniDreamerFR is describing. Really impressive. Goof for it! I bet it’s within you’re reach too.
It is a video, he lined up the jumps before so he always gets his preferred stance. I was fortunate enough to see him ride live, and I can tell you, he is pretty good at switch hops, and learning switch hops is definitely a huge advantage for muni.
You will have to make less adjustments to your line to get your cranks lined up correctly for hopping. It becomes more and more important as wheel size increases, on a 20" I can basically always use my preferred stance to hop up curbs, since I can hop up a curb from one revolution away… 
but on a 26" that possibility disappears.
What do you mean by switch hops?
Hopping with your less comfortable foot forward.
uhm why is that a switch hop. I always jump like that. My right foot is my comfortable one, which I keep on the backpedal when freemounting. To me that is more like a normal hop.
I meant with your less comfortable foot position, as in the one which is less natural. Sorry if that was confusing/unclear.