We see pro bikers "hucking" huge drops in every kind of imaginable bike media. Perhaps the mere mortal might like to huck as the the grandmasters do. Taking a drop really is extremely simple. All that it entails is a popping of the front wheel, much like in the J-Hop. However, a different strain of dropping on a mountain bike can involve pulling a wheelie off the edge at a slower speed. As I describe the process of dropping, I'm assuming that we're dealing with a 3-4 foot drop. Let's start with the easier of the two, the manual drop:

1. Make sure you are moving at a good speed as you approach the edge of the drop. Failure to do so will result in a nosedive. This would be unpleasant.
2. Pop your front wheel up as you prepare to drop the ledge. Do this by first crouching with your knees and elbows, and subsequently throwning your wieght to the rear of your bike while making a "jumping" or exploding action with your legs. Lead this backward thrust with the small of your back, and finally follow with your arms pulling on the handlebars.
3. The previous step needs to be well timed, such that your front wheel is at its peak hieght as your rear wheel drops off the ledge. It should also be noted, though, not to pop too much, as this will have you laying on your back on the low side of a 4 foot drop. However, be sure to pop enough, or a nosedive will result, which will have you on your stomach on the low side of 4 foot drop. Either scenario is none too pleasant.
4. Stay relaxed in flight. Don't straighten out. Don't scrunch up. Just look at your landing.
5. As you near landing, extend your legs a bit so that your rear wheel touches down first. Keep your weight back at this point so that your front tire doesn't smash down violently.
6. Exhale.

The wheelie drop is to be executed at at a slower speed, when a simple pop of the front wheel would not keep it in the air long enoung for the rear wheel to make it off the drop. It's a bit more of a balancing act. Don't try it until you're confident doing a wheelie on flat ground.

1. Appraoch the edge of the drop, standing up, at a slow enough speed to wheelie be sure to be in a higher gear than usual, since you pedal with more power when standing.
2. When the front wheel is at the edge of the drop, lean back and pedal up into a wheelie. Keep pedalling to sustain this wheelie until the rear wheel drops off the ledge.
3. As your rear wheel drops off the ledge, let your front wheel fall back forward just a bit to avoid going over backward.
4. Allow your rear wheel to land first, and ride on your way.