I have 1 master sheet with all the customers and there details.
12 weekly work sheets that get printed and used as daily job sheets. as we offer 6 and 12 week frequency these are set out with the customers in a fixed list making them as compact as possible, no more ordering work each night. I use google earth to locate customers positions in relation to others and arrange the week sheets in the most efficient order, which only has to be done once.
a 6 week customer appears in the list twice a 12 weeker once.
Then I have an unpaid sheet, at the end of the day any customer that didnt pay my staff at the time of the clean gets copied and pasted from the job sheet into the unpaid sheet and the date added (it takes no time at all) after 10 days I use mail merge to produce a pre written late payment letter, even 100 takes just 5 minutes to do.
Theres more to it of course like the use of colours for residential and commercial or one off cleans and so on, I use a job sheet notes field to tell my staff if extra services are being carried out and when. it flags to me if they need a text alert and so on. cant fault it, and I have tried various programmes in the past, 3 years ago I spent £3k on a custom system which a programme wrote to my design, but later we fell out and I had to come up with a solution fast, turns out what I do now works better than anything I have tried before. there are down sides but not many.