Kitty themed decorations - entire envelope should be covered - no more than a dime sized space anyplace - just be sure there is room around address so the post office can read it

Decorate with drawings, collage, stickers, Washi, sewing stitches, postage stamps, whatever you wish ... all in kitty-theme

Include a note to your partner -- more than just the swap and your swap-bot name, although please be sure to include that info, too

Let's have F-U-N -- make your kitty proud~