Have you tried flyers? Have a brochure with all your services and make it look professional, and have a yearly lawn maintenance package for the year, cutting, fertilizing, aeration etc.
Also let them know you can do more than just cut, as i have a full service client base and i do EVERYTHING for them. power washing, handy man, what ever, so instead of calling around for someone they can just ask you if you do it. I have narrowed my clients from 65 weekly to under thirty and i make more money with less as i would never just cut lawn, you make more cash doing multiple services for your clients. Also strata's are a great consistent revenue maker and with additional work it's cash in the pocket.
Hope this helps.
Jim's mowing Vancouver BC Canada.
ex mark 26'
Dodge ram 2500 diesel mega-cab
shindiawa blower, t270 trimmer
stihl km 110 stick edger
km 110 split boom hedge trimmer
km 100 mini hedge trimmer