It is important to always first read care labels carefully, and if it is recommended to 'dry clean', then make sure you take your garment to a reputable dry cleaner.
Because of the delicate nature of lingerie and intimate clothing, hand washing is always the best option. Be sure to use a mild soap and do not wring. Avoid drying them in direct sunlight as this can alter the color. Lie flat to dry and do not hang on metal hangers.
If you do insist on using a washing machine, chose a delicate cycle and at low temperature and put the lingerie in a washing bag. Do not use a high spin cycle or use a dryer.
If you care properly for your lingerie, this will ensure the garment will retain the original size, shape and color.