UV Mapping Tips for Blender

• Make sure that you’re using Blender Render (not the Cycles Render) if you want to see the results of your texture on the preview viewport. NOTE: I don’t know if this still applies on 2.8+

• Go to UV->Image view, and make sure that in edit mode, the model is UV unwrapped and that there is an image there (create a UV grid with transparency ticked off if you don’t have one)

On Seam Creation

• Try to place seams where they won’t readily be visible. Generally, the back of the head (assuming hair), split down pants and on the leg interior, jackets the area under the arm, etc.
• Seams can also go where there are natural divisions in material /texture, such as the sole vs the side of a shoe, or sharp corners of metal objects.