Please, let me know, how to take nice HQ screenshots of my homemade head texture?

Like:
or

The one on the left is an ingame screenshot. They have shaders running, and enabled raytracing in the options menu.

The image on the right is a 3D globe preview which can be done in gimp and Photoshop.

if you want to use it in gimp go to filter->Animation-> spinny globe then when the frame rate goes up it gets slower then save as gif i think