To cut a photo into a heart shape, fold the photo in half; it can be folded like a rectangle of a square depending on the shape of the photograph. Draw an outline of half a heart on the photo, starting and ending the outline at the crease of the folded photo. Cut along the outline, separate the heart shape cut-out from the rest of the photo and unfold the photograph.
Alternatively, cut out a heart shape with a regular piece of paper, and then use the paper heart as an outline for the photograph to avoid creating a crease in the photo. Make sure to stay within the lines, or else the heart will come out lopsided. The thinner the photograph, the easier it is to cut. The area around the cut-out heart can be used as a heart-shaped frame for heart shaped photographs.
It is also possible to create a heart inside of a heart. Fold the photograph or a piece of paper in half, and draw half a heart on one side of it, then draw another half a heart inside of the first half heart. Cut out the smaller heart first, and then cut out the larger heart. The larger heart is also usable as a heart shaped frame.