If your fabric shower curtain is showing some mildew near the bottom, it may be time you clean it. There are several ways to do so.
Wash Shower Curtain in Washing Machine
Read the care instructions on your shower curtain before trying to clean it. Remove your curtain from the rod and rub a wet towel over mildewed areas to loosen the mold.
Place your shower curtain into the washer machine with detergent. If the fabric is white, add a cap of bleach along with the detergent. Throw a few hand towels in the machine to run the cycle along with the shower curtain. The towels will help remove stains and scum.
Consult the instructions again. It may be easier to hang the curtain back on the rod to dry. The steam from the warm water will remove any wrinkles. You may be able to put your curtain in a machine dryer. Since the fabric is designed to dry quickly, you will only need to use a low setting.
Spot Clean When Needed
If you find only a few spots on the shower curtain, or if you would rather not wash it in the machine, you can simply spot clean the fabric. Apply detergent or soap to a wet rag. Rub rigorously to remove the stain. You may need to do so a few times to really get rid of the stain, especially if it's soap scum or mildew. For stubborn mildew, mix the soap with a small amount of bleach. Let the spot dry and hang the curtain back up on the rod.