Use a roller to paint the rest of the wall. A good method to use is the 'W method'. You start by painting a large 3 foot (0.91 m) square W on the wall. Then, without lifting the roller, you fill in the W.[7] You can paint a wall section-by-section, and do the walls one at a time for best results. It's generally a good idea to use an extension pole for your roller instead of standing on a ladder. Make sure that neither the extension pole nor the roller has plastic handles, as plastic handles are flexible and this makes it difficult to control the painting.
First, if you need it, we have it — all the paint for you home — every color you can imagine, in the finish you need, for every surface. Second, we’ can help narrow down your wall paint color choice until you decide on the right paint for your project. Of course, our paint associates at your local store can help pick our paint for your home. Pick up some paint swatches or order paint samples online so you can picture what it will look like. 
Carefully consider the gloss level. The shiny gloss paints are easy to clean, but will make any wall blemish stand out. The flat paints will help disguise wall blemishes, but can be difficult to clean. Generally, you'll want glossier paints where there's lots of steam or cooking (baths and kitchens) and in high-traffic areas. Flatter paints are preferred for large walls and ceilings.
Exterior paint averages $25-$40 a gallon, and a 3,000-square-foot home takes 15 or more gallons of paint, or $375-$600 just for the paint. However, really premium paint can cost $50-$100 a gallon, or $750-$1,500 for that large home. Doing it yourself also requires renting a pressure washer or sprayer for $50-$100 a day; extra-long ladders or scaffolding at $20-$75 daily; and a power sprayer for $50-$100 daily, plus masking tape, drop cloths and other supplies. However, it's possible to paint a large, two-story house for materials-only costs of $400-$600.

Whether you decide to do the preparation work yourself or have a professional do it as part of your project, proper preparation makes all the difference in creating a smooth and lasting finish. Do it correctly the first time or you’ll quickly end up spending more to fix peeling and chipping paint. Follow this process before starting on your home's exterior. Keep in mind that the process may vary based on your siding materials:

Homeowners report that painting a home’s exterior costs an average of $2,923 with a typical range between $1,734 and $4,119. The average price per square foot ranges from $0.50 to $3.50 depending on your location, condition of your exterior and accessibility. Stucco and brick cost an average of $1 per square foot more than vinyl or wood. The average 2,500 square feet home costs an average of $4,000, though it can range from $1,250 to $8,750.