C.N.
I have a special bra bag that I put mine in - it's sort of a short mesh cylinder that zips shut. Started using it after a wire worked its way out of a bra, into the guts of my washer, and shorted out the pump.
I wash everything in cold water with regular detergent, and I never use bleach.
I don't put them in the dryer.
I wear a bra several times before washing it. Like my jeans and towels, bras get washed when they've been used enough times that they start to smell funky.