Skydiving is a sport where you never stop learning. Even if you could, somehow, come to know everything, the sport is evolving constantly, and someone who's an expert one day is a newbie the next. Often, the learning we do isn't just academic - it can make us perform better, even keep us alive when there are problems. With that in mind, here are ten things that may keep you alive when things really hit the fan:
1. Know your limits. Everyone's limits are different, and are based on their experience, background, physical and mental fitness, and natural abilities. Some people think well under pressure, some need to drill and drill so their natural tendency to freeze is overcome. Some are incredibly flexible, some need 'crutches' (like sleeves or weight) to control their fall rate. It's important to be honest with yourself when deciding your limits, even if it goes counter to the alpha mentality that most skydivers have. We're all human.
2. Respect your limits. Don't do things you're not ready for, and don't let other people talk you into doing them. This comes up very often when women jumpers enter the sport - suddenly they have a lot of male friends who want to take them on 20 ways, free fly jumps, demos etc well before they'd ask a male jumper. And while it is technically possible to safely take someone with 20 jumps on a 20-way (you could do it with 19 AFF-JM's) it's usually a bad idea.
3. Push your limits. This may seem in contradiction to 2) but it's important. Once you know your limits, and respect them, you can start overcoming them. Do you have a problem with fall rate? Find a slow (or fast) skydiver and do a 2-way, with the other jumper going slower and slower (or faster and faster.) Is your canopy control so-so? Try drills - learn to flat turn and flare turn, a little more on each jump. Follow someone else. Do no-contact CRW. Learn to sit fly.
Pushing your limits isn't just a feel-good thing, it actually helps you survive in the sport. If you learn how to fly a small elliptical well, you will have much more control over your slightly larger square - and that can save your life if someone cuts you off on final. CRW can be fun, but can also be the difference between life and death if you have a cypres firing and have to land two canopies.
4. Push your limits, one at a time. This is even more important. It's possible to learn to do demos, as long as you learn the basics - canopy control, obstacle landings, spotting. Trying to learn these all on your first demo is asking for trouble. Small canopies, same thing. You can certainly learn to jump a VX 97. Doing it all on one jump - going from a Sabre 150 to a VX 97 - is a huge mistake. First transition down to a smaller Sabre, then learn to fly it. Then switch to an elliptical of about the same size, and learn to fly _it_. Once you get to that VX 97, you will have the background to fly it well - and you will be much, much better prepared to fly any canopy in between.
5. Learn flat and flare turns. You should be able to do a 180 in the air without your canopy diving at all, and you should be able to turn at least 45 degrees during your flare. Every year, several people die because they turn too low. I'm convinced that many of these aren't intentional hook turns, but accidental low turns to turn into the wind or avoid an obstacle. Knowing how to flat and flare turn might have saved their lives.
6. Learn more about your gear. What color is your reserve? Your reserve toggles? If you ever look above your head and see four sets of risers, how will you tell them apart? What color is your freebag? You can learn all this by watching your rigger pack your reserve, and even more by doing it yourself (under supervision, of course.)
Read up on TSO testing of your gear, and learn about the limits it was tested to. If you know that, you can keep your own flying within its operational limits. Learn about what's in a Cypres, and how it judges altitude. Learn the difference between Dacron and Spectra, and how to pack a pullout rig.
7. Get related experience. Pilots have a distinct advantage over other jumpers when something goes wrong in the plane, because they know how to read the signs, and they know how to operate around aircraft. They have a better idea what to touch and what not to touch, and can more easily communicate with the pilot (and, in rare instances, ATC.) You don't have to get your instrument rating - even a few lessons will teach you a lot about aerodynamics, aircraft weight and balance, stabilized climbs and descents, elevator trim and its importance, etc.
Or learn to climb. Serious climbers (except, possibly, sport-only climbers) are their own riggers, and understand the ideas behind an equalizing anchor, dynamic vs static rope, and nylon to nylon friction. Many of those transfer to the kind of rigging that gets done in skydiving, and if nothing else, will help you make sense of how rigs are designed.
8. Get out of your drop zone. Drop zones tend to have "flavors" to them, and are sometimes homogenous when it comes to skills or equipment. Kapowsin, for example, seems to use nothing but Infinity's, and for a while Air Adventures was nearly 100% Reflex. Some drop zones are mainly free fly, some RW, some do a lot of demos. By getting away from the familiar, you'll learn more about other disciplines, other equipment, even other ways of thinking. You'll also meet some really cool people - you can't talk to Bryan Burke, John LeBlanc, Tony Domenico or Adam Filipino, for example, and not learn something. Unfortunately, not every drop zone has them, so you have to hit the road.
9. Buy your beer. It sounds like a selfish tradition, designed to punish new jumpers. It's a whole lot more than that, though. The key is that, if you buy the beer and give it to people, they will ask you what it's for, and you will end up talking to people (up to 23) about what just happened. Since this usually happens at some significant time (say, right after your first cutaway) this is a really important time to talk about what just happened without being embarrassed about it. (Well, maybe you will be anyway, but tough.)
On the flip side - if someone buys beer for the DZ, and you're an experienced jumper, don't just grab a bottle and run. Find out who bought it and why they bought it. That beer isn't quite free - the price is that you have to pass on the knowledge that _you_ first learned when it seemed like you were buying a case every other weekend.
10. Teach others what you know. There is no better way to learn than to teach, and it helps others as well. If you want to become an expert at emergency procedures, teach part of a few first jump courses and watch other people screw their procedures up. If you want to learn a lot about RW, organize. If you want to learn more about skydiving in general, teach a graduate course. Just the act of putting everything down on paper and talking about it will lead you to research to make sure you're right, and you'll get feedback when you actually do the teaching.