I'd wash it gently by hand in the sink. Let as much water drip out as possible then lay it flat on some towels to soak up the rest of the water. When it's like 90 to 95% dry I'd iron it. This should work for you. Now, if you wash it after quilting I would tumble in the dryer on fluff or air dry until it's mostly dry. Then I would block it to make it square and try to keep it flat and minimize the "scrunch" effect. Good luck.