Having so few AERC rides on my resume, I don't feel I have the right to comment on my preference for awards, etc., but Karen C's comment about photos had me wanting to chime in.
There has seldom been a ride photographer at the rides I have been to (probably too small to warrant hiring one...?). But if you tied a ride award to a free ride photo from the photographer, that might be enough business to make the photographer's trip worthwhile? It's personal, packs light, and is always the right size! :) the photo that is, not the photographer, lol.
My mare only made it to a few LD"s and the two photos I have of her that I got, I treasure. And when I rode borrowed horses from friends, a pic was a great way to give back to them as a thank you.
and my 2 pics of my Zoeybird are worth scads more than all the tshirts I have that don't fit my short body :)