Compability of your files:

All regular naming conventions and folder-structures work:

Naming, as long as its consistent between the Image Textures, is irrelevant for ITS, you must only name the resolution somewhere in either the filepath or filename..

Image Textures:

Either have to contain the resolution at the end of the filename e.g.:

"Example_Image_Diffuse_2k.jpg" or

"Example_Image_Normal_2048.png"

Or have to contain the resolution somewhere in the filepath e.g:

".../2k_Material/(Textures)/"Example_Image_Diffuse.jpg"

".../Material_2048/(Textures)/"Example_Image_Normal.jpg"

Folder-Structure:

Either keep all Image Textures in the same folder

".../Material/Textures/"Materials_Image_Textures.."

Or use subfolders with the same suffix that the Image Textures use:

".../Material/1k/"Example_Texture_Diffuse_1k.jpg"

".../Material/2048/"Example_Texture_Normal_2048.png"

Or just skip thinking about it and use anything like:

".../2k_Material/Example_Image_Diffuse.jpg" or

.../Material_2048/.../"Example_Image_Normal.jpg"

Walkthrough (slightly outdated) available on Youtube..