Sending thank you cards is so important. They should be sent out within 3 months of your wedding. These are the people that celebrated your special day with you, and likely gave you a gift to start your new chapter. Let them know you appreciate them, and tell them how much they mean to you.
Typically, thank you cards are handwritten. It's starting to become more common to send a templated one, as long as you hand sign it before sending it off. You want it to be as personal as you can.
If they gave you money, tell them how you plan to spend the money or what you are putting it toward. If they gave a gift, let them know how excited you are about it. Even if you hate it and never use it, find at least one positive thing to say about it and express your gratitude for the thoughtfulness.
If all else fails, the least you can do is sent a standard, hand signed card. Here is an example:
JX Event Venue
123 2nd St N, Suite 301, Stillwater, MN 55082
The Loft at Studio J
214 Main St S, Stillwater, MN 55082
Mailing Address: 123 2nd St N, Suite 301
The Terrace at Stillwater Library
(Not currently booking events)
224 3rd St N, Stillwater, MN 55082