I prewash everything. I use lingerie bags. I have about 1/2 dozen and put pre-cuts or small pieces into the lingerie bags. I saw a tip the other day on another board where a gal who uses a lot of pre-cuts has lingerie bags and she bastes 4-5 strips to the lingerie bag (interior) by turning the bag inside out. This keeps the strips together without getting tangled up in the wash. It only takes a few minutes to do compared to having to untangle any at all. That is where I would use old thread from estate sales. Then turns it back outside in, zips shut, into the washer and dryer. Takes care of any preshrinkage (I always wash in hot water) then throw in dryer.