A Terrible Brush is a Watercolor Artist's Best Friend
So a lesson I learned from watching Ning Yeh's Chinese Painting basics videos was to use a terrible—well, a cheap—oil painting brush to mix colors, especially when messing around with chip colors or gamboge chunks. This reduces wear and tear on your brush, and is immensely useful as a technique because less time wasted mixing colors with your actual painting brush means less time trying to re-establish water control (which is particularly vital with all water media).
For the purposes of Chinese paints, which are quite gluey when thick, a stiffer brush is useful for distributing colors from moist chips to mixing dishes. I personally use an old Loew-Cornell size 10 shader for this, but only because I had one lying around from ages ago. You want a $1 brush for this task.
Anyways, I was surprised and frankly horrified to watch so many videos of watercolor artists, professionals and hobbyists alike, using their expensive good brushes to dig paint out of their watercolor pans. That didn't look good for the brushes and, indeed, it's not—it's a great way to kill your $60 brush in a few years or worse, when these things are supposed to last.
So to try to staunch this horror on the 'tubes, I've decided to share my tip: a horrible brush is a good mixing/digging brush for a watercolorist.
I mean, look at the brush at the top of this article. Just look at it. It has no snap and is weak, but it can hold, very briefly, a decent amount of water that can be used to moisten a cake or pan of paint. It's stiff enough—although it's not too stiff, obviously—to, after a bit of drying on a piece of paper towel, dig out color and paint thick patches onto your palette. Conveniently, basically spooning out color in this condensed form means you can more accurately measure propotions of colors for mixing.
From there you can use your good brush to get some clean water and then mix the paint patches, gently, in your hopefully gentle-on-brushes palette.
Having two brushes, one of which is rarely good for painting, may seem a bother, but for me the terrible brush is far more efficient at getting paint out because I don't have to be careful with it, and I can concentrate on controlling water and paint in my actual painting brush.
I got my terrible brush out of an old children's watercolor set. For those of us who have been around long enough to wear down a sable into a tiny mop, that can be your "terrible" mixing brush, with the added convenience that you can use it for more decent paint effects like splatters.
Now go out there and, for the love of all the gods, please don't use your good brush to dig paint out of pans.