Step 1: Go to https://www.facebook.com/thanks
Step 2: Choose a friend.
Step 3: Facebook will generate a preview of the Thanks Video. You can customize the video by selecting a different theme with different words and music (Old Friends or Friends) or editing photos and posts that represent your friendship. All of this is below the preview screen. Click a photo to include it in the video or click it again to de-select the photo. Looks like a max of 15 photos are allowed.
Step 4: Click Share. You can add a personalized message before posting. Video will post to both your timeline and your friend will be tagged. So the video will also show up on the friend’s timeline as well.
You can do an unlimited number of these videos so have fun. BUT remember that each one will be posted on your feed so give your friends a break!