I started out - years ago - just washing my fabrics in warm water
Then i had a bleed with a solid maroon when I washed that quilt.
NOW -
If the piece is big enough to warrant it, I overcast the raw edges before it hits water
Soak it (like colors) in hot water - a bucket, sink, kettle, bowl - whatever will hold it but not use a zillion gallons of water
Let it set until the water cools down - or i get back to it -
Wash - gently - in cold to warm water -
Dry - if at home, in the dryer - when away - on a line - When line drying, I fold the "good" side in and line up the selvages so that it will dry "straight"
I feel that agitation is what makes new fabric look worn/used -so I try to keep that to a minimum.
As I've said before - something I've made will probably come through most washings not too much worse for wear - UNLESS the washer is compulsive about bleach (NO NO NO NO NO) or setting it on a LOOOOONNNNGGG cycle, or washing it three times a week. (Super frequent washings only make sense to me if something liquid has come in contact with it.)