If you are inclined to keep your garden sustainable and ecologically friendly, you will use natural remedies for pest control, grow native plants and use an old-style push lawn mower. But "old-style" refers only to the concept of pushing -- modern push mowers use all sorts of "new-style" techniques to make using them as easy as using gas- or electric-guzzling, noisy, power mowers. Some models come with adjustable ergonomic handles, simple knobs to adjust blade height, and scissor-action blades that rarely need sharpening and cut grass cleanly into small pieces.
Place your mower on the grass, and measure the distance from the ground to the blades. Compare that height to the height you want your grass to be, and adjust the blade height up or down accordingly. Different grasses grow best at different heights.
Walk around your entire lawn to ensure no rocks, large sticks or small toys will interfere with mowing. Push mowers don't throw objects into the air like power mowers do, but it's still a possibility.
Select a day to mow when the grass blades are dry so you can cut them cleanly, and avoid trampling and bending the blades instead of cutting them. Wet grass can also stick to the blades and the gears of the mower.
Cut your grass when it is about 1 inch taller than the optimal height. Err on the side of leaving your grass too long rather than too short, and never cut more than one-third of its height at each mowing.
Overlap each row as you mow to ensure that you don't miss any spots. After mowing one row, position the mower so half of it is on the row you just cut and half is on a row you have not yet cut.
Mow your lawn in alternating patterns or directions each time your mow to encourage it to grow straight instead of leaning in one direction or another. Experiment with cutting in diagonal rows, straight rows, and ever-decreasing rectangles or squares.
Leave the grass clippings on the lawn to decompose and add nutrients into the soil, a practice called "grasscycling." If you know you will have an upcoming period of prolonged wet weather, rake the clippings, adding them to your compost pile if you have one or using them as mulch in flowerbeds.