I love your results. I see you are using a Wilbur shader for the shading. If you are using Photoshop you can achieve the same effect simply by using a heightmap. But get more control over it.
Copy the heightmap. Create an alpha channel. Insert your heightmap into the alpha channel. Create a new layer. Fill it with gray (half gray is sufficient). Choose filters, lighting effects. Choose endless light. In the settings, set the alpha channel with the height map. Move the sliders as you like. The most important thing is extrusion. In real time, you can extrude your map and make it three-dimensional. Now you can apply techniques to your map that real cartographers use for real maps, like Tom Patterson
https://www.shadedrelief.com/tutorials.html