all boils down to see what works best for you and that particular situation. I prewash everything because of allergies to the dyes in the fabric and fragrances. Same goes for when I baste. I must admit, I like the thread basting (Sharon Schamberg Houndstooth method. It is time consuming but basting is time consuming and spray basting is out of the question. Fragrances involved in that. Eventually, what works for you is what matters!