Being EEVEE only, and aiming to the abstract and the painterly instead of the realistic, the Sturdy shaders render real fast. With that in mind, take in some recommended EEVEE Render Engine settings:

▼ Sampling
For that extra gritty, painterly look, I prefer using less samples rather than more. All the paintings that illustrate this documentation were made with four samples using the EEVEE Viewport rendering. So there you go.

▼ Ambient Occlusion
Activate it, then crank it up. Recommended settings:
> Distance: 12m
> Factor: I’d say anything between 1 and 3, but it depends on the size of the mesh and the distance from the camera. For sometimes rewarding, unexpected results, you may try higher values.

▼ Shadows
Turn these up as well:
> Cube Size: 4096 px
> Cascade Size: 4096 px
I also prefer disabling Soft Shadows

▼ Color Management
Set View Transform to Standard, obviously