Creating and Editing Texture Coordinates (UVs) - An Introduction to Computer Graphics for Artists - page 178

Fig. 10.44 A good reference map will show the scale of your UVs, any distortion, and the location
of seams (Model courtesy of Nikihad Ali)
• Think about the kind of materials needed for the different types of objects in your
scene. Do not put UVs belonging to two different materials in the same layout.
• Layout the UVs logically, so that a texture artist can understand their relationship
to the model by looking at them casually.
• Pack the UVs as tightly as possible, without making them so close that different
polygons that are not meant to overlap share pixels due to overspray. Keep in
mind that a logical layout can be more important than a tight packing job,
depending on how much space is saved relative to how much extra trouble it is to
paint a misaligned texture.