If you're a small business owner, consultant, or contractor, it's best to ask for a retainer up front. Estimate how long a job will take and what it will cost. Ask for a payment agreement: 50 percent up front, with the rest payable when you finish the job.
This will keep your income steady and allow you to budget more effectively. Your clients and customers will also be more committed to you if they've already invested in your work. You can also offer credit card payments and installments -- this might speed up the delivery time of your payments.