Neither of my kids wanted to make their Valentines this year. At first I was sad, then I came to my senses and was happy! I couldn't just send Princess Valentines in by themselves though - so we decided to try out some molded crayons. The tray is actually a silicone ice cube tray from IKEA. We removed the wrappers, broke and cut up the crayons and stuck them in the oven. We had to use a low temperature (170 degrees) since we were using silicone instead of metal.
I found these Printable Valentines cards for attaching crayons online and used foam tape to attach the crayon. They were inserted into a Ziploc and we attached our "commercial" Princess Valentine to the front. They turned out super cute (but I'm a tad bit biased!).