Well, given my skill level, it would be launched from a bazooka...
No, but seriously, it would be very simple, no scales, no nothing, so it could be turned out en masse. It would be hardened to withstand the impact of repeated flat hits as people are learning to throw. It might even be made in two models, one of which has points on both ends, to aid in lessening the frustration of newbies who can't quite gauge distance, yet. Finally, it'd be cheap. I mean, REAL cheap. Like five bucks a hit.
Essentially, a piece of bar stock, maybe 3/16 to 1/4" thick, and 1' long, ground to a simple point or points, and hardened just enough to spring (maybe RC 48 or so? Don't know my Rockwells too well, yet). That's it. No frills. Nothing to cry over, when you miss and it goes off into the bush, lost forever. But worth buying five or six, so you can practice with the same knife over and over, to get good enough to buy custom throwers and such, and feel justified doing it.
There. I've spewed for long enough. My $.02 has stretched to about $.75, so I'll go now.
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Meddle not in the affairs of Dragons, for you are crunchy, and good with ketchup...