FOR OVERSEEDING CLOVER INTO EXISTING LAWNS
Prepare The Lawn
First, mow the grass shorter than usual and remove the clippings. Consider dethatching if your thatch layer is thicker than 0.5 inches.
Roughen The Soil
Roughen the soil using a metal rake or some other type of equipment. The more scratches and grooves you can make the better. Having your lawn aerated at this time is also a great way to prepare the soil.
Spread The Seed
Clover seed is very small, so it is beneficial to mix it with inert matter to help it distribute better. Sand is a good choice and can be added at a ratio of 2-3 parts sand to 1-part seed. Sawdust or rice hulls could also be used. After this, use a broadcast spreader on the smallest setting to sow the seed over the lawn.
Rake Again And Water
After sowing the seed, lightly rake the area again to work the seeds into the soil no more than ¼-1/8 inch deep. Keep the area constantly moist during the germination period (7-15 days).
FOR PLANTING A PURE CLOVER LAWN
Remove Existing Vegetation
Preexisting vegetation can be removed manually by tilling, digging, or with a sod-cutter. It can also be removed with a glyphosate-based herbicide applied to the area 2-3 weeks prior to planting, after which the dead plant matter can be mowed, trimmed, or raked away.
Prepare The Seedbed
After the site is clear of vegetation, till or rake to loosen and smooth out the soil surface. Remove any large stones, clumps, or other debris.
Sow, Rake and Water
Follow the steps above for spreading the seed, working the seed in, and watering.