Step 1: Hammer and Draw
Use a pencil to draw out the shape you want. This doesn’t have to be the final design but it helps to guide you along the way. Also it helps if you have an engraver to trace over your pencil mark. That way you marks won’t wipe away while your handling it. If you don’t have an engraver use a permanent marker.
Step 2: Cut, Drill, and File
Use a grinding attachment to further refine the shape.
Use hobby files to refine it even more. The files I use came from the Home Depot and cost me $16.
Step 3: Solder and Re-shape
Once you have the shape you want, solder the heart onto the other nickel. Use the same techniques to match the shape for the second heart.
The solder I use is from the plumbing section at any home improvement store. Lead free of course.