A good contractor will use his experience to make sure things go smoothly, ensuring that you get the service you want. Before you make any phone calls, put some thought into both your project and your budget. With your ideas written down, including details and a few rough sketches, you will feel much more comfortable and confident. Make sure you have the same information available for each contractor that is bidding the project. Do not change any of the details between contractor interviews or the resulting price comparisons will be meaningless.
Nothing says more about a company than how well they respond to a customers phone call.
Things always seem to come up when least expected. Sometimes it can't be helped. One missed appointment should be acceptable as long as the contractor contacted the homeowner with sufficient notice prior to missing the appointment. Are you confident that this person knows the trade and product. True trade and product knowledge is hard to fake, so ask as many questions as you feel you need to.