I prefer to meet with you, go over your needs, determine what I can do to help you (that's my business - helping you, the business owner!), and then working together to lay out a strategy for the project. At that time, I can figure up approximately how much time I will need to complete the project. What I will bring to you is a solid project cost; a set of project milestones, letting you know how much time each portion of the project will take; and a "drop dead" date for the project to be delivered to you.
I will need 50% of the cost before I begin working on the project and the final 50% within three weeks of the date I deliver your finished project to you. You will receive separate invoices for each payment.
Again, my only goal is to make YOU look GOOD, just like the old commercial: "If you don't look good, we (I) don't look good".