Clearing a jump right out of a corner can be difficult for beginners. The Seat Bouncing Techniques are usually the best techniques to use in these situations.
In order to get the most out of the seat bouncing techniques for short faced jumps really close to the corner you need to be really good at using the clutch and throttle to deliver a lot of power to the rear wheel at the precise time. To do this correctly you need to use one or two fingers on the clutch.
I prefer one finger because this way you can hold onto the grip better with the other three fingers. This enables you to get on the power hard with the clutch and throttle. You do not slip the clutch like you do when you do a start, but instead you use the clutch more like a trigger by hitting the trigger (clutch) at the precise time you need to increase the power to the rear wheel. In this situation, it would be when the rear wheel compresses into the jump. This increased power will multiply the seat bouncing technique giving you more height and distance.
Most beginner riders do not use the clutch in this way but instead depend on just the throttle alone. Even on a four-stroke you need to learn to use the clutch and throttle together in order to control the power to the rear wheel more precisely.
On longer faced jumps the clutch is not so important, sometimes you may not need to use the clutch at all, like in these photos. In these types of cases just make sure you nudge all your body weight into the seat just before it rebounds from the jump. This will cause the rear suspension to squat more in order to give more of the rebounding effect, launching you higher and further.
Out of the corner...
...prepare for launch...
...get your body forward before the landing
In both of these types of jumps, especially the shorter faced jumps, make sure you jerk back on the handlebars as you nudge your weight into the seat. This jerk, along with the power, keeps the front end from nose diving or going too low.
I hope this helps you clear those jumps right out of the corner.
About Gary Semics:
I have found that I have a real knack for teaching and it has become my goal to train Motocross riders around the world. In order to reach all you MX enthusiasts, I produced the Gary Semics Motocross Techniques DVD Series. The 3 volume series presently includes 20 technique DVDs, 2 motocross fitness training DVDs, The 2 Day MX School DVD, some other standalone DVDs, one historic DVD called "The Evolution of Motocross," 2 CDs and a Motocross Practice Manual for a total of 28 DVDs as of September 2015. The DVDs can also be Streamed.