I'm not sure how many people have tried this, but if you haven't you may want to give it a shot. Leave Behinds....it is a great way to "up-sell" your clients. If you create a form that has check list of the different services you provide and some space for a note, it will work wonders. When you are finished working at someone's home, leave them a "note" that says we were here, check off what was done and then inform them of things you suggest that could be done.... this time of the year you can suggest turning over mulch, dead-heading flower beds, aeration, seeding, leaf removal, winter fertilizer, etc.... people are busy these days and do not always have the time to walk around their property and take a close look at what needs done. If you suggest it to them and offer them an estimate, chances are they will sign up.