I see a lot of people struggling with limited income and not being able to afford all their expenses. They can't be blamed because it truly is a difficult task. Since we can't do much about our salaries from the office or income at the business, I would like to suggest a third option: earning through freelancing.
First, know that freelancing does not necessarily mean to provide services online, rather you can even freelance/work for your close relatives and friends.
We all have some sort of skills that we pick up while growing up, or at work. The idea of freelancing is to use that skill to generate more income.
If you are handy with tools, you could become a part-time freelancer that fixes mechanical problems of the people in their circle.
If you own a camera, start covering weddings as a photographer
If you are good at programming at school or work, you could start coding for the people around you, helping them with assignments or you could approach and join companies that are looking for help in their maintaining and updating their sites etc
If you're an artist, decorate homes, nurseries and kindergartens
You only have to start charging for the skills the you own. This is freelancing. Remember, you do not need to be extraordinary at the skill but you need to know it enough. You'll grow and learn with time, so you can retain your customers.