I've made picks out of just about anything imaginable (except titanium! :sad1

and I don't like metal picks. I've gone through all sorts of experiments regarding shape, size, density, width, grippy handles... I do like firm picks, I can play just fine with a totally rigid one. But I've gone pretty deep on "What
should a pick do... what
can a pick do... what
can't a pick do..." What
are these things made of, and where can I get some?"
As long as you're willing to do some modifications, one very wonderful attribute of a "great pick" is the ability to make drastically-different kinds of tones as a result of the angle you hold it at. You can only go to a the maximum thickness of 1.25mm, 1.35mm, round about there, before you start progressively losing tonal variation based on attack angle. Just applied physics. Now, you can make a 1.5mm Ultem pick a lot flatter/thinner where it contacts the strings, them buggers is tough. You can also thin out polycarbonate (Big Stubbys etc.) but it starts getting fragile if you take it too far. Most other materials begin to flex more the thinner you take them, which is sort-of exactly something you don't want - contrary direction.
The ideal point shape for maximum tone variation is - no surprise here - right around the angle of a standard Fender 351, call it 55 degrees or so, the point gets rounder. But as long as you're dicking with it, might as well take a big three-corner 346 shape to start. You can have three different points that way.
Take a 346, file it ("mill bastard" metal file is the only tool you really need, with some 220, 400 and 1500 wet-dry sandpaper); file it until there is a 0.50" long flat on each side, then round it back a bit. Shape the tips as desired, flatten 'em out - only you know what your customary angle of attack, so... think!

Ouch. I know...
What is the deal killer for me on metal picks is that as soon as you angle them they sound way, way scratchy. If that's musical to you, fine. And another thing wrong with really thick picks is that they click. If that's musical to you, fine too. You can make really thick picks out of lighter materials, but they still click - it's just a wimpier click. When I put a Milliput casting epoxy handle on a pick, the click outcome is varied by the weight conductivity of the material. Ultem is so hard most all the weight of the handle applies to the clickiness parameter. Tortex (silica-filled delrin) is less clicky, and you can go thinner if you get the point right, more on that in a bit). Clayton's "acetal" is a great material, and just soft enough to "swallow" some of the handle's weight. I'd say raw delrin, real celluloid, and silica-hardened nylon (black Jazz III's) run neck and neck. Then unhardened nylon (red Jazz III"s), then everything else is too soft. Wood picks are a really dumb idea, except as jewelry or fashion accessory. They notch.
Regarding tip shape, if you think about it (OW! OW! OW!) using the shoulder of a 351 pick is about the most variation you could ever get. When you hold it perfectly flat (parallel) you get a very clear tone, but not much glide. When you tilt it say, 10 degrees it gets faster but scrapier. If you hold it a 30 degrees, you get nothing. Swish, swish, swish. So they need to get pointier than that. But totally pointy is fairly beastial, too. If you take it to the extreme, you really need a right hand attack that is both strong and minute-motions - that combination takes a while (
years, no shirt, Shetlock) - tiny-but-strong motions. Like Bruce Lee, resting his hand ON your chest - but still able to rip your heart out. Contrast to Townsend's windmills....
So my desert island picks are an "acetal" Clayton three-corner (346) 1.26mm, modified with flatter sides; a red Dunlop Jazz III XL, point slightly rounded, with an epoxy handle; a Dunlop 1.0mm Ultex three corner, also modded in shape & with handle; and secret weapon, D'Andrea big celluloid 346 triangles, sides somewhat flattened, 5/32" smaller overall, with or without handle. 1.21mm or the "Plec" 1.5mm. All thinned and jacked with. Celluloid really does sound best, but - it notches too.
http://www.bigcitystring.com/pxcell.htm
http://www.bigcitystring.com/proplec.htm
But I usually use a thumbpick anyway. :hello2:
To me, it seems really bizarre to see somebody with 5 kinds of overdrives on his kick-board thingamajig - but only one kind of guitar pick?!? :icon_scratch:
P.S. - Around 1980-82, I made picks out of just about everything you'll ever see on eBay - steel, shells, 1/16", 1/8", 1/4" plexiglass, rocks, all them wierd woods, bones, teeth (don't ask) and I was living in Tallahassee and actually making a bit of money on them, and at least free admittance to every bar gig in town. Then Jim Dunlop came out with Tortex and the Jazz III's and crushed my hopes & DREAMS. Took me a whole six-pack to recover. These guys (Dunlop, Mark Clayton) really have figured out the best possible materials; what do you thing they do all day? And the Wegen picks are marginally "worth" it based on labor time, but spending all day to make something that a machine can make in milliseconds; well it's your money. And the Blue Chip and the Red Bear stuff is insane; IF SOMEBODY TELLS YOU TO USE A METAL FILE TO GRIND OUT THE NOTCHES, IT AIN'T NO BETTER THAN ULTEM OR ACETAL OR TORTEX. V-Picks for pete's sakes, go buy a whole sheet of lexan! Just because something is really hard to make doesn't make it any better.... it just makes it expensive. When you see people who are clearly listening through their wallet rather than their ears, ask yourself - "What is that wallet closest to?"