When your kitchen or bathroom faucet is leaking and dripping, it can be annoying and cost you money as well. However if you are the DIY type of person who skips calling a plumbing company and carrying out the faucet repair can be a good project for you to do. This will save you money and time.
It may seem hard but those who are used to carrying out simple repairs themselves, what you need to do is to learn and understand the basics of modern faucets which is not that hard. What may be a bit difficult is finding the right replacement parts, but once you get them you are good to start on your repair.

Required tools:

You will need a few tools which vary depending on which faucet you are repairing. These are:

Allen wrench to remove the handle of the faucet. It is recommended that you buy a set of small Allen wrenches. This keeps you prepared for all kinds of leaking wrenches.
Screw drivers
A large slip joint pliers

How to go about the repair

First check the faucet to determine where the leak is coming from.
Turn off the water supply preferably from the main.
Now start opening the faucet starting from the center to relieve the water pressure and also to be sure the water has been turned off.
On the sink drainer, cover with a strainer basket or rag to prevent small parts going down the drain
You do need to pay attention to the order in which you have removed the parts. You can place them on a table in the order in which you removed them or take videos of the parts as you remove if you are not able to remember. You wouldnt want a scenario where you have removed the parts but cannot remember which part goes where.
Conduct an inspection of the inside valve for bits of spoiled gaskets to be replaced or mineral deposits.
Take a piece of cloth or a nylon cleaning pad and clean the top.
Mineral deposits in the valve can be loosened by soaking in vinegar
Sometimes the water holes in the faucet can be blocked. This causes the water not to flow. Clean using a small screw driver.
You can now replace the worn out parts. Make sure that each worn out part has a replacement.
Follow the order in which you removed the parts to make sure each part fits where it should, otherwise it will be back to square one.

N/B: To be sure that you have the correct parts for replacement, source your parts from a reliable hardware. This ensures you get quality and the right parts, or else you will end up having two similar parts.
Your faucet is now repaired and ready to use.

Sounds easy right? Of course not everyone has the patience to do this and it would therefore be wise to get the help of someone with the knowledge to do it for you.