An investment in high-quality brushes is wasted if they are not properly cleaned and stored after use. So invest the two minutes it takes to do the job right.
Cleaning a brush is made easier if you remove as much of the paint from its bristles as possible. Use up what paint remains on your brush on whatever you are painting. Press the bristles against the inside of the paint can, and lift it up and out as you do: that will squeeze out more paint. Paint away the rest on newspapers.
Next, read the instructions on the can, and use the appropriate solvent. The manufacturers may specify mineral spirits or turpentine for oil-based paint; brushes used to apply latex paint usually can be cleaned with soap and water. The right solvent makes the job easy; the wrong one will probably be no help at all.
Immerse the brush in the solvent. Stir the solvent with the brush, wiping and squeezing the bristles on the sides of the container. If some of the paint has begun to dry on the brush, soaking the brush may be necessary.
Once the paint has been removed from the brush, wash it in warm soapy water in a utility sink or bucket. This cleans the brush of the solvent and remaining paint. Blot the brush dry with a clean rag or newspaper. When storing brushes, hang them up or store them flat so that the bristles don’t get bent out of shape.