The answer to 'how to unclog drain cleaning' is to use a plunger, drain snake, or chemical drain cleaner. Start by removing any standing water in the sink or tub. Then, use a plunger to create suction and dislodge the clog. If that doesn't work, use a drain snake or auger to physically break up the blockage. Chemical drain cleaners can also help dissolve organic matter causing the clog, but use caution and follow the instructions carefully.
For tough clogs or recurring issues, it's best to call a professional plumber who can inspect the pipes and use more powerful tools and techniques to clear the drain. Regular drain cleaning maintenance, such as using a drain cover and flushing the pipes, can also help prevent future clogs.