Did you know that when you’re using a tool that has a Slider, such as the layer settings in the Layers Palette, after clicking the Slider button you can use the left and right arrow keys to increase or decrease the slider by 1%. You can also hold the Shift key down while pressing the arrow keys to increase or decrease the amount by 10% at a time. This is helpful when the area you’re adjusting is subtle and you want to keep your eye on the image, instead of the slider.
