This is a hack that you’ve probably read a thousand times before, but we’re going to repeat it because it works like a charm. If the water pressure from your faucets is low, it’s probably due to a buildup of calcified buildup. You can get a professional plumber to get rid of the buildup for you, or you can use the old vinegar trick.
Fill a small bag with vinegar and place the faucet or showerhead inside the bag. Use rubber bands to keep the plastic in place, and leave the bag there for an hour or two. The vinegar will cut through the buildup like a warm knife through butter.