I keep my trade lists in my plant lists. When I'm ready to dig and send, I go through them all and write them down on paper. As I fill a box, they get x-ed out. Before sending, I put a post-it on each box with who they're going to and the address. At the PO, I use the do-it-yourself station because I never have more 4 at a time ready.
Others, have different methods but this works for me so I don't confuse myself. It's so easy to do these days.