Many things can go wrong when you're starting a lawn from seed. To ensure the best chance of success, you need to spread the lawn seeds carefully so they are buried at the proper depth and protected from the elements as much as possible. Aftercare is equally important, as seeds will fail to germinate if they are not kept sufficiently moist.
Prepare the planting area by removing all weeds, other vegetation, rocks and other debris. Loosen the top layer of soil with a rototiller or garden rake and smooth out any lumps and bumps.
Pour the grass seed into a broadcast spreader. Set the application dial to the setting indicated on the back of the grass seed bag.
Push the broadcast spreader over to one end of your planting area. Press the application lever tight to the handle and push the spreader across the planting area. It will dispense the seeds at the correct application rate in the soil.
Walk across and back across the planting area in paths close enough together that the broadcasted seeds overlap by a few inches. Continue until the entire area is covered with seed.
Rake the seeds into the top 1/4 inch of soil and mulch the planting area with a thin layer of peat moss or straw. The mulch will prevent erosion, should there be heavy rain.