Learn to use a paint sprayer and you can refinish large projects faster. Using a spray paint gun takes a bit of practice so it pays to watch an instructional video beforehand in order to avoid costly mistakes. Paint sprayers make sense for painting larger areas like walls. They are particularly good for outdoor painting. Because there is always over-spray, preparation work must be precise. You must mask every single thing you don't want painted.
Beginners might want to start with an electric cup-style paint sprayer. These have a gun fitted on top of a paint reservoir. They only hold about a quart of paint so you'll be dealing with frequent refills. More expensive air paint sprayers work with a compressor. You can also choose an airless sprayer connected to a source of high air pressure. All paint sprayers are somewhat difficult to clean. It takes time and effort but it is an essential part of the process.