Depending on the type of pipe(s) you have, you may not always be able to stop a clog, but you can try to prevent it. For main lines, watch what you flush, no paper towels, feminine products, or wipes of any kind. On small lines like sinks and tubs, you can run hot water for a minute or two after using soap. That will prolong a clog, however, soap suds turn to grease in lines and will eventually cause the drain to stop up.