Instead of using vinyl lettering I just printed the words on cardstock and we placed the paper into the frame. The girls can write what they are thankful for as they go through the month- and they can invite family members to add things as well. I used a free typewriter font and a free image (I photo edited mine to make it black and white) off of the web.
I used the clever idea of writing on the glass with an ultra fine sharpie marker- it doesn't smear like dry erase markers but wipes off easily with a damp cloth- another great idea from the brown paper packages blog!
During activity day we also played gratitude charades where the girls acted out what they were thankful for and we all guessed. The person who guessed correctly had the next turn.
The girls also took home a small "gratitude" journal- a 99 cent notebook from WalMart.
We used this talk for our discussion on being grateful. Hope that helps.