The Static Hop: One burst to go.

The static hop helps in situations where there is no room for a run-up, with the front wheel already up on some corner.
To start, you should be already in balance with the front wheel up onto some edge, bench, kerb, rails, or pallets.
1° From there, flex down on the bike as much as you can to prepare the impulsion. Keep the brakes full-on all the time.	2° Extend to the maximum in one hop, pushing on the legs to jump but also with the arms to boost your impulsion on the bars (the front wheel is static).	3° To follow up with the impulsion, you should pull on the bars to lift the bike forward, while lifting up the knees to let the bike go up.
See the move in an animated gif

More tips? The best places to practice are stairways, or small wood logs. At the beginning, try to feel the move on some easy stairways, like if you were throwing away the bike in front of you. To boost the impulsion, really try to bounce back from your flexion by using the spring of both your legs and arms. When you get the right move, you can land directly on balance one step higher, either with the front wheel on the next higher step, or directly on the rear wheel. If the front wheel is not too high on the edge to climb, you can even try to combine it with a pedal kick.

Flexing to hop/push on the bars.

The ultimate climbing technique is to Bang the front wheel onto the obstacle. Really a move for the pros, for walls up to....well, I guess it depends on your motivation...Kenny (three times world champion in mountain bike trials riding, in the junior category) goes up to about 1.40 metres.