Clean shower glass doors with glass cleaner, vinegar or baking soda. Use a soft sponge, microfiber cloth or squeegee to remove scum and also to avoid scratching the glass.
Glass cleaner is good for everyday use, but if soap scum builds up something stronger may be needed. One option is to heat vinegar until it boils. After the vinegar cools down, use it to wipe down the doors and watch as it cuts effectively through mold and mildew stains. Another homemade option is to mix baking soda with water or baking soda with liquid dish detergent to make a paste. Rub the paste on the glass, and use a sponge to gently wipe it and the scum off. Using a squeegee after each shower can also help prevent scum and mold build up and can lengthen the time period between more extensive cleanings.