My cousin Annie got married back in 2010 and since I was the Maid of Honor, I helped my Aunt Sharon plan and execute a (beautiful, if I do say so myself) bridal shower for the soon-to-be Mrs. My aunt had the idea to do a "vintage mermaid" themed party, and gave me the reigns to come up with an invitation.
Since I was already designing the wedding invitations and they were going to be super fancy, I decided to go cute and casual with the shower invites. I googled "vintage mermaid tattoo" to find some inspiration for my mermaid drawing. Once I had the mermaid done, the rest of it fell into place. I didn't think to add the message in a bottle on the envelope until I was writing the poem and came up with the line "washed up with the tide". So glad I thought of it--I think it adds a nice touch!
**Update-- March 2015** This invite is still one of my best-sellers on Etsy, and since 2010 I've made some updates to the colors and envelope, both of which can be customized when you order!