Photoshop Tip: Global Layer Styles
Tips & Tutorials, by Mark White
May 26, 2012
Remove the Global Light option from your Layer Styles
In most cases you’ll want consistent lighting throughout an image, but there may be a time when this is not what you’re going for.
When applying layer styles, untick Use Global Light next to Angle to mix up the direction of Drop Shadows and Bevels, for example.