i changed to seasonal agreements or contracts, however you want to call them. its over seven months May to November. I bill first of May and ask for payment by end of the month. That way I am basically paid for the months work at the end of that month. Worked really well. many pay right away others middle of month, some end of the month.
Seems to be chqs in the mail everyday. Best of all I never second guess myself. I just cut it, it always looks better after its cut.