If soap is your shaving lubricant of choice, then a brush is crucial for ensuring proper application. The traditional shaving brush has been around for centuries, with a design that has remained classically consistent; long bristles and a smooth handle that can be held between thumb and forefinger.
The most important part of a shaving brush is the bristles, used for their ability to hold significant amounts of water which can be mixed effectively with shaving soap to create the perfect, rich and luxurious lather. Thicker and more emollient lather translates to less razor skipping and dragging; resulting in a closer and cleaner shave.
Bristles also have the ability to lift hairs and stubble up off the skin, which leaves facial hair softer and more easily removed by a razor. This process also leads shaving brushes to act as an exfoliator, as they help to remove dirt and dead skin and reducing blemishes.
The final benefit of a shaving brush is perhaps less quantifiable, but we think using a brush definitely makes shaving more enjoyable. Using a nice, effective piece of equipment improves any task, so invest in a brush and start looking forward to your daily shave.