Using normal maps, specular maps, occlusion maps, and parallax maps is the best way to make your art appear much more realistic, as materials that use them will act realistically when in range of lights and other objects.
Download Laigter: https://azagaya.itch.io/laigter
Timestamps:
0:00 What do they do?
0:42 Making Maps
2:04 Implementing the Maps
3:24 Trying them out
4:57 Subscribe :)