Find a heart or simple Valentine's Day image that would make a pretty paper chain. Use coloring books or old Valentine's Day cards and decorations you don't mind cutting up. Or search online — many websites offer free Valentine's Day clip art. Look for balanced images, ones that have identical elements on both sides. Remember, you'll only be using half of the image as your template, so the other half must match up or the hearts won't look right when the chain is unfolded.
Trace half of the chosen image onto tracing paper. Draw a straight line where the middle of the image should be and only make a detailed drawing of half the heart shape up to the vertical line you made. The other half will be made automatically by the scissor cuts in the folding paper. Make changes to the design where necessary for cutout areas. Draw cutouts within the image from the middle line inwards. Erase any unwanted lines from your drawing.
Place a sheet of clear plastic acetate on your work desk and tape the top edge to your work space. Place a carbon sheet on top of the acetate and tape it to the work space. Place your finalized drawing on top of the carbon sheet. To make it easier to cut the intricate design into the acetate, place the vertical line of the half-heart against either the right or left edge of the acetate.
Trace around the heart image. Press down as you trace so that the carbon markings are dark on the acetate.
Remove the drawing and the carbon paper. Darken the light carbon lines on the acetate with a marker.
Starting from the outside edge of the acetate, cut out the outline of the heart image. Press the point of the scissors into the template to cut out decorative elements that are in the center of the image. The shape you cut out from the acetate is your paper chain template.
Draw the outline of the template on your folded paper and carefully trace any of decorative elements within the image — trace all indentations and holes that appear in the template. Cut the folded paper along these traced lines and unfold the paper to reveal a heart-shaped paper chain.