Minor nitpick. They care about results, a reasonable approximation of costs, and most importantly, the delivery date.
Those are the 3 points of negotiation. Or rather 2 points. If a client is asking you to compromise on quality to reduce cost or delivery date, walk away.
So 2 points of negotiation. How much it costs and when will it be delivered.
Whatever you decide on the costs, make sure you can 100% deliver on the date agreed to. If you're late by even a day, you will ruin the relationship. That isn't to say they won't work with you anymore, but the relationship will become more difficult. It's as if you lied to them, however unintentionally.
Always deliver on time.
As far as how you break it down and bill them ... they don't really care. I bill by the week, day, hour, and sometimes by project ... whichever suits me at the moment or whichever I feel suits the client best.
Those are the 3 points of negotiation. Or rather 2 points. If a client is asking you to compromise on quality to reduce cost or delivery date, walk away.
So 2 points of negotiation. How much it costs and when will it be delivered.
Whatever you decide on the costs, make sure you can 100% deliver on the date agreed to. If you're late by even a day, you will ruin the relationship. That isn't to say they won't work with you anymore, but the relationship will become more difficult. It's as if you lied to them, however unintentionally.
Always deliver on time.
As far as how you break it down and bill them ... they don't really care. I bill by the week, day, hour, and sometimes by project ... whichever suits me at the moment or whichever I feel suits the client best.