To be more specific, cleaning acrylic paint off paintbrushes. The easy way is to clean them often. This is my method but I only paint in 20 minute increments so I only get one or two paintbrushes loaded with paint. I wet my brushes before I use them and that seems to lessen the amount of cleaning I need to do later. I use a paint brush holder that holds the brushes in water.
After I’m finished painting I immediately wash the brushes I’ve used (usually only one or two). I wash them in water and hand soap. I was trained with oils and washing the brushes in turpentine was tiresome. I liked the original smell of turpentine but cleaning the brushes was a little arduous; acrylics are much better.