To make wood heart cutouts, you'll need to use a scroll saw. If you don't have experience using one, read the manual or talk to an experienced woodworker before you begin. Make sure there's plenty of overhead lighting so you can see your work from all angles.
Use a uniform heart shape as a template for your cutouts. If you decide to draw it yourself, fold the paper in half and draw half a heart, then cut the shape out.
Trace your pattern onto a piece of plywood that's between 1/4- and 1/2-inch thick. Make sure the piece of wood you choose is large enough to accommodate your heart-shaped pattern.
Turn on the scroll saw and guide the wood along the blade in the pattern you traced. Remember to turn the wood to make the cuts and keep the scroll saw stationary.
Sand the heart shape to remove slivers or rough edges.
You can also use a band saw, jig saw or hand saw to cut out heart shapes. It'll take a bit more time and you'll need to sand more with these tools than if you use a scroll saw.
Put on safety goggles and a dust mask before you begin to cut out the heart shape with your scroll saw.