It happens so many times when I do a demonstration that someone will say to me that you make it look so easy when using your watercolor brush to make it do so many different things. 

I tell my students that art supplies don't come with any instructions and definitely they don't come with paintbrushes. So how do you learn or know how to use a brush if you never had read the instructions or tried a brush for the first time to make it do something you have never done before? The answer is that you have to practice and play around with your brush before you can use it to paint a watercolor painting.

Now you are probably wondering how does one practice and learn how to use a brush. It's quite simple, one needs to practice with it a lot, and not on a painting but on a scrap sheet of paper, and try to practice doing all sorts of different brush strokes with it. 

Use a piece of scrap paper and fill it up with all sorts of random and different brush strokes using all kinds of different amounts of water to pigment ratio in your brush. Try some brush strokes using a lot of water in your brush and sometimes try more paint than water. Try different strokes, like some can be long and skinny, and then try poking the brush directly onto the paper. Try as many different combinations of paint to water ratios and as many different strokes as you can think up. Try to remember what you did so you can do it again when you need to get a certain look out of the brush techniques that you practiced. 

Practicing while not actually doing a painting is so important for learning how to work techniques with the brushes and paint you use. Also, make sure you do this with many different brushes so you can tell when it is a good time to use a small brush compared to a big brush and also when to use a round brush compared to a flat brush.

Practicing with your brushes will help you in learning how to use your brushes since they don't come with instructions.

Practice makes perfect!