My big realization is that I tend to think of myself as a watercolor painter but really I paint these days in acrylic and acrylic gouache.
To honor that change I've moved my FORTUNE in high end watercolors down a few drawers in my easy access wire storage tower. Now I have the acrylics in the top drawer with the awesome Sennelier acrylics really at my fingertips. Tubes of acrylgouache that I use for squirting out of the tube seascapes are also handy.
I am ditching years of saved watercolor paper of the inferior variety. I haven't thrown away art yet, just art supplies I don't use, and paper.
Of course, I'm recycling the paper and art supplies into my sandbox student art supply sessions next term.
I also ditched a bunch of the way-too-many half-used sketchbooks and am recycling the sketchbooks with blank pages to my classes too. I now have only 2 baskets full :-) and the third basket is full of handy sized mat board that has made my work more easily sellable of late. I really enjoyed selling the little oceans to the family at Christmas.