Remove the drain stopper or stopper assembly
Pull out visible hair and debris with a gloved hand, needle-nose pliers, or a drain tool
Use a plunger to create suction over the drain
Pour boiling water down the drain if the pipes are metal
Add baking soda, then vinegar, let it sit, and flush with hot water
Use a drain snake or auger to break up and pull out the clog
Remove and clean the overflow plate and linkage if needed
Check and clean the P-trap if accessible
Flush the drain with hot water after clearing the clog
Repeat the process if the water still drains slowly
Call a plumber if the clog remains or the drain backs up repeatedly