We do a Valentine treasure hunt with candy at the end for the kids...and we used to put a little gift with a large Hershey kiss. Seems like the gifts get bigger each year. We graduated from a small stuffed animal to a movie to a Lego set to something video game related for the son.
Here are some free digis to help you get started on Valentines. I think I'll use some of these for cards or tags, even though you could also use them for scrapbooking. It's from Papercrafts magazine's site and you can download them in jpg or pdf form. I especially like the the alphabet card.
Here's some free cute Valentine art from Sweet Clipart.
And if you're looking for an image to color, check out this cute bee from Paper Smooches and their free art. They also have hearts and other free stamps that would work for Valentine's Day.
This free image is from Hannah Lynn Designs. And you could add a different sentiment if you're going for a Valentine card...but I think I might just use her as is on a Smash Book page after I color her a little more. Looovvveee Hannah Lynn drawings and digi stamps. They are perfect if you like Copics, watercolor pencils or colored pencils. Fun to color!
One of my favorite sites for FREE vintage graphics is The Graphics Fairy. This rose is from an 1868 children's magazine. Lovely!