I buy fat quarters, 1/2 yard and 1 yard bundles of fabric, and I chose Bella snow as my main go to for light solids on my work, and black from Bella for my darks. I find if I keep solids to the same basic colors from the same manufacturer my life will be easier.
I do have a huge selection of charm packs and jelly rolls too, but I have been very disappointed in the lack of consistency in the sizes, as such I no longer buy them.