Whether you are using a push mower or a lawn tractor Here are a few basic guidelines for proper mowing your lawn.
Walk the area you are mowing and remove any stones, sticks or other debris.
The proper blade adjustment for mowing height is determined by what type of grass you have. I have found that on my lawn two inches works best. Do a sample cut and measure the length of the cut grass. The grass left standing after mowing should be around two inches in length. Do not remove more than one third of the total length of the grass. Keep the mowers blade or blades sharp. You want your lawn to look like it was cut not chewed.
Don't cut wet grass. This can cause uneven mowing and the wet clippings can mat and restrict light to your grass. There is also the danger of slipping on slopes or grades.
Avoid sharp turns with the mower or tractor. Sharp turns will cause the wheels to dig into your lawn.
Don't mow in the same direction every time, doing this will compact the soil and show wear patterns in your lawn.
If your lawn has uneven or high spots take care mowing those areas to avoid scalping the high spots. Scalping is bad for the lawn but even worse for your mowers blade.
Doing a little online research on the type of grass you have will provide you with even more information on the proper mowing and care of your lawn.