For the inside I added a square piece of the same cardstock (I should have made it a bit smaller) and a clip to hold the money in place (I always worry about it falling out when you just set it in there.) I also like to put a little bit of matching patterned paper on the inside of the card too.
I decided to decorate the outside of the envelope and I put his name on crooked but that is ok...he won't mind. I was in a hurry and had to finish making the envelope and inside of the card while he ran out to the store real quick. lol =D
Thanks for looking!