Whether you are at the kitchen sink, bathtub, or utility sink:
Avoid chemical drain openers for a clogged drain. Instead, use boiling water or a drain snake.
Never pour cooking oil or grease down the drain.
Never pour oil or latex based paints, solvents, or large volumes of toxic cleaners down the drain.
Eliminate the use of a garbage disposal. This will significantly reduce the amount of fats, grease, and solids that enter the sewer system.