According to Emily Post
You should send a thank you note (not a fill-in-the-blank cards, no pre-printed cards, no phone calls, no emails and no generic post on your website) to anyone who gave you a gift, gave money, helped out on the big day, vendors, and the folks who hosted your shower or party.
To read up on more do's and don'ts please visit Emily Post for a great reference on sending thanks you notes.
On a positive note (pun intended) you now have another excuse to browse through beautiful stationary as you create your thank you cards. And again as we've mentioned so many times in our posts it can be another way to carry your wedding details and themes to the very finish. CT- Designs actually posted a blog earlier this year about sending wedding photo thank you cards as an idea. You can check out that post here.
CT-Design original work
For some writing tips and a really great story check out this spot on NPR.