Regular maintenance is key to avoiding the gruesome cleanup of mold and mildew, and using a shower spray each day after you bathe is the easiest way to maintain a clean shower without a lot of effort. Soap scum is notoriously difficult to remove once it has set in, so a daily wipe will make all the difference.
The biggest problem with soap scum is that it's not easy to spot at first. It settles in as a thin, filmy buildup that blends in with your tub, but from there it can grow into dark mildew and even mold. This is especially true in the grout between tiles. Mildew and mold need water to flourish, so the surest way to avoid the outbreak is to wipe down your shower walls and doors with a dry towel after you bathe. If you have a curtain, spread it out completely after you shower so it can air out.
Your choice of soap can influence the buildup of soap scum as well, and that's an easy thing to change. Bar soap often contains talc, one of the main things that causes the filmy buildup on shower and bathroom tiles. Liquid castile soap and other kinds of shower gels are typically easier on porcelain shower tiles and tub floors. Simply making this switch can help you keep a cleaner, mold-free shower.