OP I've got some tips that might help, but the most important factors when dropping cliffs (or hitting park jumps for that matter) are confidence and commitment. If you aren't confident that you are going to stomp your landings then you probably won't. If you aren't committed to the drop than you will most likely make last minute defensive maneuvers that are going to get you into trouble. So that being said, you are going to have to get over your fears first. Can you tear your ACL hucking a 10 footer? Absolutely. Can you tear your ACL walking down the street? Absolutely. If you are a skier, the possibility of a knee injury comes with the territory. Skiers are 365 times more likely to tear a ligament in their knee than non-skiers. It can happen dropping cliffs just as easily as it can happen walking from your car to the lift. My point is that, while tearing your knee is a completely rational fear, if you are going to be an aggressive skier you need to stop dwelling on the bad things that might happen.
So moving on, once you have developed the confidence to commit to dropping some cliffs, here are a few tips that might help:
*Do some investigation first! Scope the drop from above and below. Probe the landing to make sure you aren't landing on anything that can hurt you. Make mental notes about the approach, the drop, and the landing. Is the approach really steep? What is the trajectory of the takeoff? Does the drop require that you air over rocks or trees? What kind of landing should you expect and how are you going to control speed after you land? Also keep in mind that cliffs usually look very different when you are standing on top of them. Depending on the size of the cliff you may or may not be able to see the landing. While investigating you should be creating a mental image of all of the details. The more investigation you do, the more confident you will feel about a particular cliff.
*Make a plan for your approach, takeoff, and landing! After you have done your investigation you should have a pretty good idea of how much speed you should carry into the drop in order to reach your landing. You should also have a pretty good idea of where you are going to negotiate turns after your landing to control speed. Visualizing the drop in your head from start to finish is paramount. If you can visualize it you can probably do it! With regard to the approach, I recommend standing on top of the drop and sidestepping up to where you want to begin your approach. Start from a place where you can ski straight into the drop without making any turns. This way you can focus on the cliff, not the two or three turns leading up to the drop. Figure out the speed you need! I'm of the opinion that speed is your friend. Think of it like riding a bike. The faster you go the easier it is to balance. I cringe every time I see someone ski too slow into a cliff or jump because I already know what the outcome is going to be; they are going to roll down the windows like an out of control gaper and they are going to land in the backseat, backslap, and possibly tear a knee. I know it is counter intuitive to most but it is simple physics; an object in motion will stay in motion, while an object at rest will stay at rest. Remember that you will accelerate at roughly 9.86m/s every second while in the air. If you are moving very slowly at takeoff, your body will try to stay where it is while gravity pulls in a different direction. The result is that you get into the backseat, which makes negotiating landings difficult and dangerous.
*Takeoff. What sort of takeoff do you have? In my opinion, takeoffs can take 3 general forms; downward, flat, or upward. Upward takeoffs are probably the most difficult because they tend to pop you into the air and the trajectory is the furthest away from your desired landing position. Downward or flat takeoffs are much easier (although downward can also be very difficult if the slope is very steep because it makes speed control on the approach more complicated.) I recommend starting with a flat takeoff. Below is a picture that shows a flat takeoff.
*Landing. If you look closely at my skis you can see that they are almost parallel with my landing surface (although you can't exactly see the landing in this photo). If you look at my hands you can see that they are in front of my knees. The key to stomping any air is to land with as much of your ski as possible. You never want to land on your tips or tails. Land on your feet. In almost every case your landing is going to be on a slope. Let's think about this for a second. If your takeoff is "flat" and your landing is on a slope, you need to drive your weight forward in order to match your skis to the landing. This involves some core strength as well as some subtle manipulation of your skis using your feet and knees. Not only can you use your 6 pack abs to keep your upper body over your knees and toes, but you can flex your ankles or bend your knees to change the angle of your skis in the air. If I flex my ankles my tips go up. If I bend my knees and pretend like I'm kicking myself in the butt, my tips drop. I can use a combination of these tools to make sure my weight stays forward throughout the drop and that I land on as much of my ski as possible.
*Landing continued. Just because you land on your feet doesn't mean that your done. You still have to ski away like a boss. The biggest mistake that most people make is that they try to control their speed too quickly after landing. Remember that you are accelerating while in the air and traveling pretty fast by the time you land. If you rush to control speed you are going to eat it. Land. Regain balance and control. And then think about making some turns. On a small drop (5'-8') you may be able to jump back into some short radius turns. On larger drops, think about negotiating medium to large radius turns. Think about the big boys being filmed from helicopters dropping cliffs down huge faces in AK (Mark Abma, Sage Cattabriga-Alosa, Seth Morrison, etc.). I would describe their turns after landing as huge radius. The bigger the drop and the faster you are traveling, the longer it is going to take to effectively control speed. This is why scoping your landing and developing an exit strategy BEFORE you hit a cliff is so important.
I know it is a lot but I hope there is something in there that helps. A couple other things to remember:
*Get comfortable catching air, whether it is on park jumps, moguls, or a trampoline.
*Watch other people. Identify what they did correct. Identify what they did wrong. Replicate the good and avoid the bad.
And since this is a cliff thread and I love catching air, here are a couple pics from the last couple years.