Rake the grass with a garden rake to remove rocks and other debris that may damage the aerator.
Place lawn flags or other markers on the lawn to signify the location of sprinkler heads or other fixtures in the lawn. Avoid running over shallow roots and other hard objects that may damage the aerator.
Check the lawn for moisture. Dry soil will not benefit from plug aeration. Lawns that are soaking wet will also not provide an optimum platform on which to aerate. Wet a hard lawn's soil with a sprinkler two days before aerating.
Start the lawn aerator and make medium-paced passes over the entire lawn. Repeat the passes going in an opposite direction.
Leave the plugs on the lawn to provide nutrients to the lawn as they decompose.