A great technique to for DH riding is the manual. Similar to the manual front wheel lift found in the Advanced section however balance is maintained on the rear wheel allowing the front wheel to remain off the ground far longer.
In some respects the manual is similar to wheelie. Where the wheelie is performed seated and uses pedal power to start and maintain the lift of the front wheel the manual is performed standing and uses rider weight shift to loft the front end.
This advantages of this are that lifting the front wheel can be performed much qucker without the need for a pedalstroke. Being performed out of the saddle it also still allows the rider to use their legs to absorb and pump the trail.
This technique can be used in a rhythm or tabletop section to maintain or even increase speed by pumpin the backside of the jumps when you enter too fast to keep both wheels on the ground allowing you to keep your center of mass higher than if you let the front wheel drop.
When you first start practising the manual pick a quiet place with a gentle downslope. Being able to maintain a wheelie will help you recognise the balance point but is not essential.
Start with a manual front wheel lift remembering to cover your rear brake in case you go to far. Lift the front wheel around 18" or 45cm off the ground.
Move your weight further back and lower down than you would for a short wheel lift putting your backside over the rear wheel almost as if you are trying to sit on top of it
Once there move your hips forward and back to find the balance point. If the front wheel drops extend your legs and move your hipd further back..
If it feels like the bike wants to loop out, bend your legs slightly and move your hips forward a little. Use your knees and hips to steer and maintain sideways balance.
If you get too far off the back a gentle dab of the rear brake will bring the front down again. Brake gently rather than grabbing a mitt full and you may be able to save the manual as the front end drops slowly.
Use a manual to negotiate those alpine drainage by pushing the rear wheel down into them whilst keeping the front end high enough to clear the other side. This technique uses less effort and can get you across wider ditches at any given speed than a bunnyhop.