Jumping advise :)

Right before you hit the jump accerate and as your front time leaves the ramp let off the gas . Any adjusting in the air can be done like this:
Gas hard to get the back down
Hit the rear brake to bring the back up

I don't hit alot of big jumps either:)

All you consiously have to do it just let off the gas as soon as you become airborne. Jump in 2nd or 3rd gear mid at first and use powerband as a extra boost to launch you further later on. I wrote a more in depth article on beginner jumping but really you wont apply the ideas here until maybe a year of motocross racing. Here it is anyways...

-Jumping-
extablish an aggressive body stance and allow
your knees and arms to bend to absorb the compression and rebound of your
suspension.
This stance is the general racing stance and has your butt 4-8 inches off the rear of the
seat with your knees bent and semi-stiff. Your head should be 2-3 inches behind the
crossbar of your handlebars and your upper arms should be 20 degrees up from parallel to the ground ,and finally your lower arm bent 30 degrees up. In this position you will find your self
ready for almost any non turn obstacle.
When approaching the jump, do not chop the throttle! Keep the gas steady, close to
the 3/4 of the gear so that you have room to create a gyroscopic effect to lift your
front or drop it down. You can jump in any part of the gear but you may find your self
overrevving and with no way to keep your nose up in powerband. In lower revs you
might not having enough torque to clear the jump or keep your nose up.
Chopping the throttle or letting off as soon as your in the air usually is enough technique for a good landing but sometimes more complex landings or jump designs require a more advanced technique.
On the face make sure you keep your knees flexible or you will get thrown forward
and possibly over the handlebars in mid-air(i know from experience) The rebound will
kick back and now you will be airborne. Your airtime should be spent entirly on
preparing for the landing, NO TRICKS YET!, the biggest problem with jumping is
keeping your nose on target. If you are landing on flat ground then your landing will
come naturally just keep it straight like you were still on the ground with these
techniques.

A.Nose up
1. Increase throttle
2.Lean Back
B.Nose Down
1.Lower throttle( use clutch to stop engine from stalling)
2.Lean forward
3.Rear Brake(Lowers front side)

The other remaining tactic (Front brake) is for slope landing use only because of the angle you land at. A downsloped landing may not come naturally because it will look like your going to
crash at first, this is normal and you need to ignore it. Landing flat on a slope will shock
you pretty hard and may result in a get-off.

C.Front Brake(Raises rear)

Keeping the dirt bike parallel to the ground is the first part of a sloped landing, after
that you have to determine when to use the brake. This period in time always occurs
before the beginning of the landing but will vary depending on the height, angle and
speed of your motorcycle. The brake pull has to slow your tire to a stop or very near
stop to start your alignment process. If this angle is attained too early before you land
you will need to use gas to keep a steady nose. Chopping the throttle at the last split second your rear wheel is in contact with the ground before becoming airborne will bring your nose down also.

Never use the rear brake in the air without clutch

Keep your wheelspin/actual speed ratio close to 1.2/1

You will usually want to land under power or else your suspension will be too soft and
may bottom from a large g-load.

Never land without power on sand.

Dont even think freestyle until you have all types of jumps mastered! Not even a 1
hander, it may result in a bad mis-angled crash!

Dont enter powerband on or wheelie off jump faces

Thats all you need to know about jumping

The short, abrupt "backyard track" jumps aren't exactly friendly to learning how to jump. I like jumps with no kickers or severe change in angle, with a tall enough ramp (at least one bike length). The ramp should either become steeper all the way, or have a constant angle.

Don't be afraid to land with the front wheel first a little bit. Modern dirt bikes take this quite well, and some even land softer this way.

FMX-please explain more on the front brake technique...I have fooled around with this when I was bored, but it didn't seem to have much of a useful purpose other than a complete panic situation where you are flipping it (and in that case it's hard to hit both brakes). I found that it isn't too cool to land with the front wheel stopped.

Yep, stopping the front wheel is a no-no.

The nice thing about stopping the rear wheel is that if it brings the front down too much, you can hit the gas and bring it back up. (Watch some of the crazies doing the 150+ foot jumps and you'll see that they see-saw the bike back and forth many times while in the air.) If you stop the front wheel, there is no way to get it restarted before landing.

Also, having the front wheel spinning makes it behave like a gyroscope and you can turn the front wheel to alter the attitude of the bike in the air. If the front tire is stopped, you lose that ability.

Also, as motopuffs mentioned, short jumps are difficult because the front tire is already in the air by the time that the back tire hits the jump. This usually kicks the back end up and the front down violently. Larger jumps are actually much easier, except for the pucker-powered throttle limitting action. :)

FMXN, I'm also really curious as to how you know when you've got 1.2:1 wheelspin and why that is the desired ratio.