Create and send invoices on the spot from your computer, tablet or smart phone.
Be flexible about payment methods. If you accept credit cards and carry a credit card reader, you could accept payment at the job.
Take a deposit up front for a large job.
Send a polite reminder a couple of days before your invoice is due for payment.
Monitor your Accounts Receivable Report and chase as soon as a payment is overdue.
Collect your fees by direct debit, for example GoCardless.