If you change the first default setting below, your thumb won't have to work as hard.
If you change the second, your composition may improve.
If you use aperture-priority or shutter-priority exposure modes, you may find yourself scrolling through innumerable numbers to change the exposure.
Most cameras are set by default to change lens openings and shutter speeds by 1/3-stop increments.
While this is a noticeable change, the change is small.
You probably don't need to change the exposure settings by 1/3-stop increments.
Look in your camera's menu, such as in the custom settings menu section, for the way to change the EV stops to a 1/2-stop increment.
If you need to fine tune an exposure, you can always bracket your exposures by 1/3 stops using the exposure compensation feature.
Some cameras can be set to display a tic-tac-toe grid in the viewfinder.
The grid can be used to apply the rule of thirds guideline.
The lines also make it easier to photograph level horizons, formal gardens, interiors, and buildings.