A comment to my last post included, "I have preferred, even more, contractors that went a little further than the contract specified". While this is jumping ahead a bit (I was getting to that), this might be a good time to talk about it a little.
It is always a good idea to go the extra mile to make sure you have really satisfied your customer. But what you have to realize is that your customer, more often than not, expects to get the baker's dozen.
It might be in the form of an extra piece of trim or it might be in the form of a little shelf in the closet. I once had a customer ask me to run matching crown around their entire living room. They actually expected me to throw it in even though it represented a couple of hundred dollars worth of custom milled molding and at least a day's work for two guys. But whatever form the little something extra takes, you can bet that it will not have been included in your contract.
It became my practice to add a couple of percent to my total quotes to allow some wiggle room at the end of the job to cover these little somethings. If it was within reason, I would usually do it just to keep everyone happy. If the request, like the room full of crown, was too much to absorb, I would suggest we split the difference, still giving the customer the sense of getting the extra. In the case of the crown molding customer, I kind of smiled and said, "Sure I can throw it in. And I'm sure you would mind throwing in an extra couple hundred dollars either, right?"