Nobody wants to talk about this...
When should you charge your customers?
Answer: When they are happiest with you. A happy customer recognizes value and will gladly pay for it.
How do you get customers to pay an initial deposit?
Answer: By asking for it. Refuse to do any work until you’ve both signed an agreement and are satisfied with the terms. Include the deposit in this agreement. This puts both of you at ease with the risks you’re taking.
How do you raise your rates without losing your customers?
Answer: Balance their pain with pleasure. Provide new features, free upgrades, or other perks. Give plenty of advance warning and increase in reasonable increments. Position the rate hike alongside extra value and the change will be acceptable.