I wash my new fabric as soon as I get it. That way I can store it with the rest of my stash and not have to worry about what's been washed and what hasn't. Reds get washed in hot water, and everything else gets washed in warm. Then I throw it all in the dryer on low heat. I only use a little bit of detergent, and no fabric softener. Afterwards, everything is carefully folded and is kept in a cat-free room, much to their disappointment. ;-)
Finished quilts get washed before they're given away, to fluff them up and make them extra-cuddly. (And to make sure everything holds up properly! LOL! So far, so good.)