I would say you got to get to burning a bunch of BP motors! What you got to fly them on?
Well, I used to have a ton of C's. I stocked up at a local hobby shop before moving, and I don't usually use anything smaller than a C unless it's really windy, because I'm foolish like that, and apparently I need an excuse to buy more rockets.
So most of them have been Estes kits. The C6-7's were for the Quest Quadrunner (I need more than the two I have left), and the only C6-3 I have left is for the Big Bertha.
Also, for some reason, I never bought that many D's. I really like the E9 (I've never had a CATO on those. Must have missed the infamous batch number), so I kind of didn't have the D12's on my radar, but whenever I see them fly at a club, I really like them.
The E's have mostly flown on scratch builds, which I've tended to lose in the scrub (#YOLO - You Only Launch Once). My newly completed Astron Sprint XL clone uses those. The first flight went up on a D12, and came back with no damage. I didn't get video - I couldn't get my camera to turn on. But the flight was weird - it wiggled as it rolled on the way up. Not a corkscrew, exactly. More like a... well, picture an LP with an off-center hole. Like that. May be that it was packed oddly. I'll have to see how she does on the E9's.
The 24mm composites I got for a scratch build I did after a design from the book
Make: Rockets: Down-to-Earth Rocket Science by Mike Westerfield. The original design is your basic motor-hook-thrust-ring design with surface mounted fins. I souped it up a little with a screw-on retainer and radially-tapered sort of Nike style TTW fins, and it's a great rocket! Holds a hidden camera. It's called the Ceres B.
The hidden camera...
The fins...
And the G40's will fly on my nearly-complete PSII's -
Nike Smoke and
Ventris.
The H133 will go into my
Leviathan for my L1 attempt.