Laying grass seed is much less expensive than laying sod or sprigs, but also more difficult. Grass seed can be finicky, so it's important to keep cultural conditions just right to maximize germination rates. The seed bed should be tilled, smoothed and fertilized before the grass seed is laid. Once grass seed is down, watering it will be your top priority. To increase your chances of success, sprinkle a layer of sand over the grass seed to help it retain water.
Broadcast a light covering (less than 1/4 inch) of sand over the grass seed. Sprinkle the sand over the ground by hand in small lawns or use a broadcast spreader with holes small enough to broadcast sand. Make two passes over the lawn, 90 degrees to each other, to ensure even coverage.
Increase the grass seed's contact with the sand and soil by pressing it down with an empty lawn roller. Make two passes over the lawn, at 90-degree angles to each other. If you do not have a lawn roller, simply walking over the lawn will ensure good contact.
Water the soil with 1 to 2 inches of water (more for sandy soils) so the top few inches of soil are moist but not soaked.