Step 1: Grab your address listRemember when you (or a family member)
[my mom] gathered your guests’ names and addresses when you sent off those wedding invites? Grab that list so you don’t have to backtrack. If you can print them off your computer with a label-making program, half of your work is done already!
Step 2: Get your gift-givers straightMost gift registries keep a master list of who gave you what, so print out a copy. For all the people who went off your registry, the sooner you jot down what they gave you, the better (before postwedding brain freeze sets in).
[it has]Step 3: Divide and conquerSplit up the task with your spouse during commercial breaks
[during the Jazz game] (have him do his friends and family, and you do yours). Try for 10 a night.
[I did 11 on Sunday, sucka.] Is one of you on a writer’s strike? At least agree to sign the card so both of your names are there. Hint: The person who doesn’t write the cards becomes the envelope-licker and stamp-sticker.
Step 4: Start writing
[good tip]Just like you don't want to open a boring gift, no one wants to read a boring thank-you. Say why you love the item, thank them for their support, or mention something funny, like how they were a dance machine at your reception. If the gift was money, mention how you plan to use it (house down payment, amazing honeymoon). Once it’s signed and sealed, put a fat checkmark next to the guest's name and beg your new spouse for a quickie hand-massage. Phew, just a few more to go!
Source:
http://www.thenest.com/