Have you seen the Box Card!? If not I would be shocked. These great, fun and cute cards are all over Pinterest and Crafting blogs right now. The ideas for these are endless and they fold up and fit in a envelope! Love it!
I saw a similar card to this on Pinterest and when one of my friends and clients had her baby last month I could not resist Casing it! Zoo Babies is one of my favourite stamp sets and a perfect fit for this card!
I used the I am Me DSP for it's fun, bright colours.
To finish off the card you add a panel on the back for your sentiments and such. Below is a link to a tutorial and video I found from Angie at Chic n' Scratch! These are so fun, I even made another for an upcoming club!