Dear Customer,
I do the similar things everyday, so that guarantees the highest quality of my work.
The schema of my work is following:
First step is to clarify the scope of project and Your expectations, this let us avoid misunderstandings during settlement.
Second step is my work. I do project according to agreement.
Third step is presentation of work I've done to You.
Fourth step is approval of my work by You.
Fifth when work is approved - You make a payment. I do not require milestone payments, so you don't risk any money.