Ideas, make a few dollars more by planting bulbs. Tulip, daffodils, hyacinth, crocus, snowdrops.
Spreading bark mulch, of course.
Maybe treating the bark with pre-emergent.
Maybe there are local favorites, plant bushes, and perennials.
Take soil samples for soil tests. Use pH meter. Send to a lab--OR--do them yourself with a top-notch soil test kit. Charge for this--or--do it free for goodwill--and to prove that your company is better than your sleazy competition. Find the percent sand, silt, clay and organic matter.
Maybe you can learn how to do a soil biology (soil health) test. There must be a kit somewhere. Or a special lab.
Overseed rye on Bermuda for winter green?
Dormant seeding? Or overseeding? Using improved cultivars of turf-type tall fescue? Not many people believe in this--so--you would have to guarantee satisfaction. In theory, the seed would sprout in spring when the soil temps reach about 55.