i always pre-wash everything before i use it. i try to do it as soon as it hits my door, but it doesn't always happen that way.
i use the hottest water, detergent and the dryer. if it had a chemical smell, then i wash 2x. i always wash reds alone. there has been bad bleeding.
same with blues. if they still bleed after 3x, they go out the door. i don't trust retayne for the long haul. i'd rather replace the piece.
before i cut i press, except for the backing, which i spray on the quilting frame. i starch as i cut and piece.
i toss the batting in the dryer with hot wet towels to shrink those. i don't like surprise birthday parties either.