Palm muting is one of those things that most of us can't even remember a time in which it wasn't second nature. That being said, I've noticed many players, students or otherwise, whose playing indicates a lack of consideration for certain mechanical aspects.
Everything from the angle of the pick, position of the hand on the bridge, picking direction, and even the rotation of your wrist makes a drastic difference in tone.
Many players, when first learning this fundamental technique, aren't taught to go into depth with many of those ideas. This results in a limited array of sounds that a player can produce.
For examples of all the potential varieties to this seemingly simplistic technique, take a look at the following video:
Thanks for reading/watching!
By Kevin Goetz