One of the all-tip wedding etiquette questions that I’m asked is about Thank You notes.  I still love to receive a handwritten, well thought-out note.  I know it’s more of a hassle and so easy to send out invitations and thank you’s via internet, but make it a fun challenge to hand write your thank you notes whenever possible.
Over at Jetting to the Wedding, she has so much advice on etiquette as well as several other ideas for your diy wedding.