For small, 'regular' shoots, I don't think trinkets (per se) are much of a big thing, one way or another.
Fun, well-run shoots & good atmosphere are more important to most, I think.
That said, you have to price the shoots accordingly: an embossed Shamrock bag for each class winner, cheap buckles for 2 & 3 ... people will pay $25 for 'targets & trophies'.
Bragging Rights shoots, $18. Throw a green bird and have a mid-50 pot for a couple of bucks extra.
Pie & Meat shoots are always popular, too.
Steal other folk's successful ideas shamelessly, of course. Invite other clubs, and go to their shoots, too.
The secret is to build participation ... then poll the shooters what they want.
Pick up the phone and talk to BGC, Fennville, OGC, WCGC ... Mike Hessong* at Victoria in Texas about 'fun shoots', etc.
Bob