Because we skipped the typical late-August aerification this year, we double aerified the greens.
One set was a deep-tine aerifier, making a 3/4" hole about 10" deep.
The other set was done by our own walk-behind machine, making 3/4" holes about 5" deep, covering about 10% of our surface area. Sand was applied prior to making the holes, allowing the tines to push the sand down. Once the sand was dry, the surface was dragged to move the remaining sand into all the holes.