Before you call the plumber to complain about the crummy water pressure in your bathroom, first confirm that the shower head isn't to blame. After all, mineral deposits can build up over time, reducing the rate of flow. In other words, you may just need to clean that shower head. One option is to detach the fixture and laboriously scrub each of its component parts. Alternatively, try this: Fill a ziplock bag with vinegar, then secure the bag in place over the shower head and leave it there overnight. The next morning, wake up to enjoy the best shower you've had in months!