Consider mother nature
Plan ahead when painting, select a dry time of the year when there is little rain and lower humidity.
Quality over price
Better quality paint means you will paint fewer times over the years and get better coverage when you paint.
Wash and sand
Paint wont adhere very well to dirty or rough surfaces, so be sure to clean the exterior first.
Paint from top to bottom
Starting at the top and working your way down while painting helps control streaks.