I assume for mixing you mean on the palette.

Watercolour paint is a weird thing. If you mix too much on the palette it looses “liveliness” and becomes “flat” – just my opinion. My view is one should mix as little and as little as possible on the palette, and preferably directly on the paper. It gives a better result. Too much mixing results in mud.

And, with less mixing going on, there is less damage to precious brushes, and therefore no need to have a separate mixing brush, and no loss of precious pigment left on the mixing brush.

Yes, I use cheap brushes for mixing, and also things like scrubbing and lifting. I’m very good at bending the ends of brushes and so using cheap brushes makes my good ones last much longer.

If I need a very large wash, then yes. I use full pans, and make them pliable enough with glycerin and binder, so using regular brushes and mops is usually not an issue.

I have not found it necessary to have a separate brush to get paint from the paint wells. I rehydrate the paint at the beginning of the painting session and don’t dig in the paint with the tip. I lay the half of the side of the tuft on the paint in the well to pick up paint. I also don’t push with the brush when painting and only pull the brush in the painting stroke. Pushing the brush is hard on the tuft.

I often enjoy using a water brush for mixing. The paint can be moistened by squeezed out water, and again when making the puddle. This way less paint is wasted when cleaning the brush in the water container. It works nice for large light puddles, but not so well for dark colors.

It depends on what brush I’m using main on my work. If it’s my Rosemary R9(squirrel) I’m less gentle and don’t use a separate brush to mix, if my main for the piece is my Escoda Reserva(sable), there’s a fair chance I’ll mix with a separate brush

What tends to deteriorate watercolor brushes, particularly round brushes of any fiber, is using the tip of the brush to lift and “dig out” partially dry watercolor paint from the palette wells. This is a bad habit and death for brushes!

To solve this problem, simply: 1) Spray and hydrate all paint before using. Wait 5-10 minutes after spraying before using. Better yet, spray and then add fresh paint; 2) Always use the belly of the bush (not the tip) to lift paint out of the palette wells and introduce it to the palette’s mixing area.

These simply two steps will go a long way in preserving the tips of brushes.

Sling paint,
Virgil