Clear a clogged drain by pouring a 1/2 cup of baking soda into it, followed by 1 cup of vinegar. It will bubble and foam, and once that stops, ﬂush the drain with hot water. About 5 minutes later, rinse with cold water. This approach is effective, non-toxic, and less damaging to your pipes (and wallet!) than commercial drain cleaners.
Related: Quick Tip — Fixing a Clogged Drain