Preen. Water, spot treat for weeds.
Water in the mornings, so as to not get fungus growth from overnight watering)
My FIL was a VP for a major lawn care company and won Ohio Turfgrass man of the year award a few years ago( which i reallize means nothing to most of you, but it's a big deal in the agronomy world) He maintains our yard, that's the basic just of what does for us. If your yard is shoddy now, it can take a few years to make it really nice. Figure out your problem areas areas and focus on those this year, IMHO.
He suggested preen over Scotts because it's same chemicals, cheaper price.
Root depth is important too, remember that as long as your grass is, is as long as it's roots are, so if you mow on the shortest height, your roots have no length, and therefore need much more waterings during dry months. We mow once a week, during mowing season, on the highest setting.
We spottreat with a chemical that get at meijers that's specific to dandelions.