When mowing the lawn, leave the grass clippings on the lawn instead of raking or sweeping them up. Grass clippings can add nutrients such as nitrogen back into the lawn and, contrary to popular belief, don't add to thatch buildup. Clippings from a regular mower are okay as long as the lawn isn't too tall when mowed, but using a mulching mower is even better since it chops the clippings smaller, making them decompose more quickly. The rules are simple. Mowing fairly high keeps the roots cooler, improves water retention, and promotes dense turf.
Dense turf prevents weeds from germinating.
If your lawn looks like a war zone in the morning with shallow holes all over, it's probably skunk damage. Skunks feed at night on grubs living in the soil. In spring the grubs are closer to the surface and easier for hungry skunks to dig out. To get rid of skunks, get rid of the grubs. These microscopic organisms will parasitize the grubs and kill them.