have you ever tried to create a simple, printable 3D object like a coin, pendant, earring or medal based on your own drafts? It could be quite time consuming if you are not familiar with powerful 3D modelling software. eXtrudy might be a good solution for your problem since it helps you to create two sided objects from your photos and drawings.
Unlike common 2D-to-3D web applications it provides individual shapes, two sided objects, multiple decoration elements (engravings), hooks, volume calculation, .obj file export and a lot more. It actually took me nearly 2 years of my free time to complete it and I would describe it as quite stable.
The picture below shows an amulet with a paw imprint of our dog. It took me only a few minutes to create it. The resulting object file has been uploaded to a 3D printing service. Check out my tutorials on youtube to see how it works.