I went through my stash of page protectors and decided to use a DESIGN F Project Life Page Protector. There just enough 3x4 pockets for the valentines.
Here's the front: I used a 4x6 title card from the Project Life Love themed set. I just added some wood veneer accents and a extra "love mail" card I found in my scraps.
The valentines were both double-sided and single-sided, which made for a weird look on the back. I left the double-sided valentines alone so we would have to take the them out of the pockets to read the messages. For the single-sided ones, I just chose 3x4 filler cards from the Love themed card set to cover the backs. The 4x6 card here is from the same set and I just added embellishments.
I Love the way it turned out and I think from now on, I'll do something similar to this.