Big brush and lots of water! This is what I tell people that want to loosen up their watercolour technique. These brushes hold A LOT of water and pigment but the fine point allows you to attend to fine details as well.
The best part is the price, at $85.00 this is less expensive than some synthetic hair brushes in this size range.
I included a ruler picture to show the scale of the brush. I have this entire line of brushes available to try in my shop. Makes a great gift for the artist in your life.