The best way to fix a leaking faucet depends on the cause of the leak. Here are a few common causes of faucet leaks and the best ways to fix them:

Worn washer: A worn washer is a common cause of faucet leaks. To fix this, you will need to turn off the water supply to the faucet, disassemble the faucet and replace the worn washer.

Corroded valve seat: If the valve seat is corroded, it can cause a leak. To fix this, you will need to remove the faucet and clean or replace the valve seat.

Loose handle: A loose handle can cause a faucet to leak. To fix this, you will need to tighten the handle with a wrench.

Damaged O-ring: A damaged O-ring can cause a faucet to leak. To fix this, you will need to replace the O-ring.

Cartridge replacement: Some faucets have a cartridge that controls the flow of water through the faucet. If the cartridge is worn or damaged, it can cause a leak. To fix this, you will need to replace the cartridge.

It’s important to note that if you are not familiar with plumbing and faucet repairs, it’s best to call a licensed plumber to fix the leak. Not only they will have the proper tools, knowledge, and experience but also you will be covered by their insurance in case any further damages occur.