Mow your lawn. It should not be any higher than three inches.
Knock down any extra shrubs or trees on your property, as ticks nest in them.
Put up a fence to keep out deer, if deer are a nuisance. Deer and rodents are the carriers of the black-legged ticks that cause Lyme disease.
Cover your property with pyrethroid, which is a pyrethrum-formulated pesticide designed for getting rid of ticks. You can buy it in liquid or granular form, but the granular form is recommended for use in the yard. If you have heavy vegetation, you should use the liquid form.