Have you noticed that when you have a solid, well thought out payment schedule included in your contract, and you insist your customers abide by that schedule, you have fewer problems?
A good payment schedule keeps your customer focused on their part of the job and helps you by establishing a good cash flow.
If you have a poor payment schedule, i.e. 1/3 down, 1/3 at 2/3 of the way through the job and the final 1/3 at the end, customers seem to think this is an open invitation to gripe and grumble about the job. “Your price is too high”, “You’re not 2/3 done”, “I’m not going to pay until . . “, etc, etc.
Get paid every two weeks, and hold your customers to the contract. You will eliminate many problems when you make that adjustment.