This heart bookmark, designed by the amazing Francesco Guarnieri, is an elegant yet simple bookmark. It would make a great Valentine day's gift I am sure :) 

The design includes a whole lot of pre-creasing followed by collapsing heart into shape. Step 8 in the diagram is the most difficult step I think. But if the mountain and valley folds are followed accurately, this shouldn't be a very difficult task. 

I used 80 gsm paper with little hearts printed on it. Small sized squares work best. The 3-inch square I had used, resulted in a 1.5 inch heart, perfect for a book corner. 

Model Details:

Model: Heart Bookmark 

Creator: Francesco Guarnieri

Difficulty Level: Low Intermediate

Paper Ratio: Square

Paper Size: 3 inch squares

Model Size: ~1.5 inches across

Diagram: Origami-cdo