If you decide to paint multiple rooms in your home, choose colors that relate to one another without being completely the same -- unless uniformity is your goal, of course. Costs may vary based on differences in color, gloss and room size. However, each room will flow depending on the trim's color -- which should all be white or neutral -- so they look connected. A whole-house color scheme presents the same cost factors as painting multiple rooms individually: colors you choose, the gloss, the size of the rooms and time/labor. You can choose to use the same color throughout your entire home to save on money, or you can use a color scheme with the same gloss throughout, though this isn't recommended for selling purposes.
Inspect the surface area for holes, cracks or other problems and apply acrylic caulk to fill them in. Use a putty knife to smooth out the caulk and remove any excess to prevent bumps. For particularly thin or narrow crevices, you may have to use your finger to smooth out the caulk. Caulk contracts and shrinks, so apply a second layer once it's dried.
I have a Home Improvement/Painting business, and Angie's List always advertises that that everyone is out to get them. Of course there are people who try to take advantage of homeowners My reputation and repeat business is based on word of mouth. Shoddy work is always a way to get put out of business quick. As far as strictly painting, preparation is a big factor in getting a quality paint job. If you don't prepare the surfaces you are painting you are spinning your wheels, and wasting money, no matter what paint you use. Getting a deposit from a customer is beneficial, but not always necessary. Sometimes it is a godsend, when you get stuck by the customer, which has happened to me more than once