I have done the weekly thing, and that was a hassle and a big waste of gas. Either they would be sleeping, not home, or what have you then I would have to drive back out there again to pick up the payment.
I switched to monthly similar to what you described. I work the month, then on the last day I make up the invoices, and mail them out. Payment is due by the 15th of the next month. If I don't receive payment before the morning of the 16th you get charged with a $10 fee, and I cut you from the schedule until I receive payment. I also charge a dollar a day until the account reaches $30 in late fees. (not sure if this is legal need to check into that part, I believe it is because there is a cap which is what I have read online planning to go to a lawyer to find out for sure) I have one customer who hired me in may signed an agreement that says she has to give me a 30 notice before she can cancel and I the same. No notice no pay for her. I have another who just recently owes for two mowes, and when I showed up on the 15th to mow expecting she would pay, her lawn was already mowed and said she didn't need me. she tells me she can't pay some hospital emergency, so I tried to be nice and not charge her for the mowing that would have been completed in the 30 day period, but would charge her the late fee and dollar a day. she comes back with an additude saying she will pay the 10 but not the dollar a day. I explained it was in the agreement that she signed along with the 30 day cancelation, needless to say i still haven't been paid. I go to her house to see if she would pay today (car in the driveway I know it is her car because her kids go to the same school as mine which is where she saw the sign on the van to call me in the first place) her daughter answers the door and says her mom isn't home. FUNNY!!!
Needless to say, next year and or any new customers will have to pay up front each month! The ones that I already have seem to pay on time and most either already pay a month in advance or they pay when I show up, or call a couple days later to have me pick up the payment. Not sure how that will work but I am tired of not getting paid by ****** bags that think I work for free! How would they feel if they went to work expecting to get their pay check and it wasn't there and they gave some excuse as to why they couldn't pay them?
As far as the automatic billing, I am not sure that too many would actually sign up for that and if they did you would collect the info have them sign an agreement stating that you have the ability to charge them x amount each month on said day then sign up for a credit card processing like square that allows you to manually enter the info (they charge more for this) not sure if they have to sign if you enter manually or not