I recently bought zip-up clear sweater bags and some shelves to stack them on. I sorted the yarn by how I think of it--tweed, variegated cotton, solid cotton, super-soft, solids wool, 'other fibers' like silk, soy, corn.
I also have some hanging shoe shelves that hold my nice-to-look-at yarns like Lorna's Laces and Noro. I like leaving them where I can see them.
I used to keep it all in collapsible hampers after going through the solid storage bin stage, but I had to move them around too much to get to what I wanted.
Having them in the clear bags lets me just look for what I want, or just look to remind myself what I have.