Create a ‘rule-of-thirds’ grid
Don’t use the grid view very often? Then turn it into a rule-of-thirds grid. In Photo-shop, press Command-K (PC: Ctrl-K) to open your Preferences. Click on Guides, Grid & Slices from the list on the left and change the settings for the Grid section as follows: Gridline every 100 percent, Subdivisions 3, and click OK. This creates a grid that divides the image into thirds both horizontally and vertically. When you turn on the grid by pressing Command-‘ (PC: Ctrl-‘(apostrophe)), a rule-of-thirds grid will be superimposed over the image.
Simple, elegant and useful. Great tip.