I also made smaller hearts, not shown, which can easily be used for party decorations, favors, and a great way to give little gifts, not to mention if you have little kiddos this is a great way for them to give little valentines to their friends, they can stuff the pinata with chocolates.
What you need
Cardboard (boxes or cereal box)
Cut two identical heart shapes in cardboard. It can be as small or as big as you want it to be.
Tape the two hearts together using a strip of cardboard in between them. The strip can be as thick or as thin as you want the heart to be. Don't forget to make a little door to put goodies in it.
Cut small slits of fringe on the bottom half of the streamer paper.
Because of the shape of the heart, I recommend gluing mini strips of the streamer paper along the sides of the heart first.
Next, glue paper in overlapping rows horizontally across the front of the heart.
Until you go all the way to the top. Repeat on the back side of the heart.