Nudging

Nudging a layer changes its position 1/10th of a point, in any direction, using the arrow keys on your keyboard. If you plan to nudge a layer in the Layer or Adjustments tabs (this does not create animation over time), select the layer in the Preview window first, then use your arrow keys to nudge your layer. If the layer isn’t selected in the Preview tab first, pressing the arrow keys will cycle through icons, slides, and layers instead of changing the position of your layer. 

If you have position keyframes set for your layer in the Animations tab, be sure to select the correct keyframe first before nudging your layer. Text Layers, Solids and Gradients, Masking and Adjustment layers can also be nudged using the same arrow keys.