I usually include buttons and stickers with every rack order I ship because everyone likes to get extra schwag when something comes in the mail. You can order these buttons here, by the way (or not): http://cetmacargo.com/products/cetma-cargo-buttons.
This weekend I'll begin silk-screening CETMA shop rags, which will soon be included free with all CETMA rack orders. I do this because I'm proud of my work and thankful and I mean it. Confession: I stole the shop rag idea from a guy I know who builds crazy motorcycles and does a lot of cocaine.