I soak my fabric in HOT water (separated by colors on this round - in case there is a bleeder- dark green on dark green does not bother me too much) - in a sink, a bucket, a bowl - depending on the size of the piece of the fabric.
After the fabric passes the hot water phase (water is clear or almost clear) - then I wash it on a brief gentle cycle in lots of water with only a small amount of regular gentle detergent - and then dry it.
I think keeping the agitation to a minimum and leaving "room" in the dryer and washer help minimize abrasion of the fabric and helps prevent that "worn" look.