Water the lawn well a day or two in advance to promote better plug pulls. You can over-seed your lawn right after aeration, then fertilizer over the seeds. This is the BEST way to improve your turf thickness and to fill in bare spots. Purchase grass seed from a local garden center, that way you'll know the seed will grow well in your lawn (not a generic brand sold in a box store that is sold all over the country). If you want to add a fourth step...top dress over the entire lawn after aerating, seeding, and fertilizing. Use the back side of a metal rack to smooth over the compost. Some people rake the plugs after aerating, especially if top dressing. For top dressing use a well-composted soil amendment or top soil. If seeding, be sure to water at least twice a day when temperatures are getting in the 70s.