You can make your grass greener and thicker by making it accessible to 3 different things: sun, water, and good soil.
Your lawn's sun exposure is controlled by your property. The only things that could really hinder the amount of sun your lawn receives are trees and the side of your house.
Rain water alone is good for a mature lawn, but for a new lawn, you'll want to supplement it with watering. If you're looking to make your grass even thicker and greener, a watering regimen is recommended, no matter the age of your lawn.
It's important that your soil has all the nutrients it needs. Soil is predisposed to give off nutrients to the grass, but oftentimes, certain chemicals can prevent the grass from accessing these nutrients. This is where a proactive, well-rounded lawn care program can really help.
At Hambleton Lawn & Landscape, we don't actually treat the blade of grass, but the soil. Our lawn care program consists of a fertilizer and weed killer. The fertilizer helps feed the lawn, while the weed killer helps to keep the weeds away and prevent them from weakening the lawn.
In a nutshell, for a greener, thicker lawn, make sure your lawn gets enough sunlight and water throughout the day. Also make sure that your soil has a good fertilizer. Whether you're going it yourself or through a lawn care program, this will give it all the nutrients it needs and allow the grass to absorb nutrients already in the soil.