This technique is a fun and easy way to soften up your painting. It just takes a little bit of thinned-out white and the right brushes and you're right as rain!
Below are the links to the types of supplies I used in this video:
Flat Sable Brush (can be synthetic):
I used this for the crosshatch wash effect.
I used this for feathering (diffusing) certain areas of the paint.
I'm an affiliate of Blick Art Materials which is where I get this cleaner. I've been a customer for a long time because their prices are so good and they have an amazing selection of art products in one place. If you use any of the links above to place an order, I get a small commission but it doesn't affect you at all... you just help out a fellow artist! If you have any questions, you can email me at firstname.lastname@example.org
Rinse the brush in warm water until it runs clear, tap out water but leave the brush damp.
Swirl your brush around in the cleaner, making sure to get between the bristles. I also find it helpful to use my fingers to get between the bristles and scrub around a bit if it needs extra help.
Rinse in warm water, tap out excess water and allow to dry.
After your brush is dry, you can run your fingers through the bristles to reform them if necessary. I think you'll find they are in so much better shape then using standard water or cleansing solutions.
If you find there is still a little bit of paint on the brush you can repeat the steps as necessary. I normally only need to do it once for normal painting sessions, but do what works best for you!