I will visit you to discuss what you're looking for and provide a written quote with a fixed price for labour (notwithstanding changes in scope) and an estimate cost of materials.
The prices for materials can fluctuate (up and down) but I simply pass these on at cost and can provide receipts if you require.
Provided you're happy with the quote we can discuss a work schedule and completion date. I will request a deposit in advance, which will also secure the delivery date. A second payment is due upon starting work.
Once completed I issue an invoice for the final amount, minus the first two payments.