I'll admit it, I was totally one of those girls who would fold heart-shaped love notes and give them to the cute boys in my class. I even received some back (and I still have them!). There are a ton of tutorials on how to make the fold, so I won't add to the number, simply link you to the best one I found.
You remember them now?? The fun part is, I have a huge stack of cute scrapbook paper - no lined paper for me anymore. My hubby will be getting this baby in his lunch with a special love note on the inside: