I'd read everything I could on drysuits (because I read everything I can about just about anything). Then one day, I saw one on sale... and precisely my size, too.
It arrived on a Friday, just before lunch, so I rushed home and tried it on. It fit very well, although it took me probably 10-15 minutes to get it back off. (Thankfully, I don't have to punch an actual clock for lunch.) I headed back to work.
Well, it just so happens that I was heading to Florida for a couple days of boat diving. In fact, I was leaving that very evening. I resigned myself to having to dive wet one more time, since there wasn't time to get up to speed. Then I thought of something. The person with whom I was carpooling didn't get off work for another... hmm... four hours or so... and I'm sitting here with a new drysuit... and my parents have a pool in their backyard...
Well, I headed over to their backyard, all my gear (and lots of extra lead) in tow. A few minutes later, I was sculling around in eight feet of water, thinking, "You know, I should've bought a hood" (my hooded vest was obviously not going to work :biggrin
. I spent a tank of air sculling and looping and somersaulting. Rolling onto my right side and hearing all the air leaving from my shoulder dump became annoying, then became solved. I practiced everything I could come up with, and then, as if on schedule, I heard a great continuous "BWOOOOOOOOOOOOSH" sound.
I looked toward the surface, and wouldn't you know, I had a huge fountain of air coming from behind my head. Taking that as my cue to call the dive, I proceeded in a controlled fashion to the surface, where I inflated my BC and drysuit and then reached behind myself to turn off the valve before the tank ran dry through the blown O-ring. (I noted that I could indeed still reach my valve while in the water in the drysuit; I had tried earlier on the patio.) I doffed the gear and packed everything up for Florida.
Seeing as my first open-water drysuit dives were in the Gulf in 70-80 feet of water, I told my buddy that I'd like to ascend along the anchor line instead of doing a free ascent directly to the boat (as we normally do when there's no current). I also dove the suit with a bit more squeeze than I now consider normal (using my BC for buoyancy control), and I had a bit more lead than I "need", although when diving dry, there isn't a "right" answer to "How much weight should I wear?" -- you balance ballast against thermal comfort against gas-space management. (Note, however, that the "right answer" is ethereal, but the *wrong* answer is concrete: wear less than you need to stay down with a fully-exhausted suit and empty tank(s), and Neptune will extract his revenge in calories and air... or worse.)
Anyway, not using the drysuit as primary buoyancy means that I've never had an uncontrolled ascent. (I have had one downward-swimming shallow stop... until I found a nice big rock -- how convenient that dive was in a quarry, eh? :biggrin
Now, I use my BC (wing) as primary buoyancy, but I intentionally send some air to my legs as well. That leaves me in a nice extra-stable tripod position, which makes for a very relaxing dive.
(Or, for the short answer, "Yes, I'm self-taught.")
Incidentally, there just aren't that many drysuit divers in Baton Rouge, it seems. I probably got better results by reading and learning from "real" drysuit divers on ScubaBoard than I would've had by taking a course from someone who rarely, if ever, dives dry. The best a course would be is having an instructor read the book with me and then tell me to follow the instructions. :biggrin:
When my usual buddy picks up a drysuit (which, I'm told, will be soon -- they don't want to hear about all my diving all winter *again*), they'll have the benefit of practicing with someone who actually dives a drysuit. Admittedly, I'm not an instructor, and I'm not going to recommend the "drysuit as primary buoyancy" method, but I have a feeling we're not going to have many problems.
). 
