Dry off your faucet. You don't want water to dilute the cleaning products you apply.
Apply diluted hydrochloric acid to the faucet. This can be purchased in most cleaning sections at either your neighborhood grocery store or home improvement store. Allow the cleaner to sit for a few moments.
Clean the faucet with a hard-bristled toothbrush. Do not scrub too hard, or the diluted hydrochloric acid may splash onto nearby carpet, towels or clothing and stain it.
Rinse off and clean the faucets with a clean, damp rag, and then dry it.
Spray the faucet with an all-purpose bathroom cleaner at least once a week. This reduces the need to clean with diluted hydrochloric acid. Make sure to wipe down the faucet at least once a day, to keep water from sitting on it and causing more water spots.