Good posture is vital for so many different reasons. But today when we sit more than ever, and especially with computer-based jobs, it is not weird that our posture seems to get worse. A good posture helps us to keep bones and joints in correct alignment so that we can properly use our muscles. It prevents us from injuring ourselves, both in exercising and in daily life. It reduces the stress on our ligaments and even allows the muscles to work more effectively. 
Muscle weakness, lack of flexibility or sitting too much are some common reasons as to why you could have bad posture, but there are ways to fix it!
A proper posture (called athletic posture) should look like this:
- Feet should point straight forward
- Hips should be slightly pushed forward so that your back is flat.
- Shoulders slightly pulled back, and chest pushed forward
- Chin slightly tucked in
Try to become more aware of how you stand in your daily life, that itself is a good start of improving your posture. On top of that, there are a few things you actually can do yourself:
Strengthen your core
A strong core makes a huge difference for your posture, as the core muscles support the spine. Many people will immediately think of sit-ups, but there are more effective ways to do it. Do exercises that stabilize the core muscles instead, such as balance exercises on a pilates ball for example. Functional training means that you use your muscles in a way you would do in your daily life, and in that way it becomes both more useful and practical.
Yoga yourself to a better posture
Yoga seems to be improving posture, as you work with both flexibility and strength. In a lot of yoga there’s a big focus on the core, so naturally, you will develop stronger core muscles. But don’t underestimate the power of flexibility! Often our bad posture comes from stiff muscles, and to really stretch out your muscles will make a big difference. With more mobility in back and shoulders, you will be able to stand more correctly.
Work on your habits
Try to evaluate your moving habits, to become more aware of how you stand, sit and lay down. Every time you become aware that you’re hunching your back, correct it. It can be hard in the beginning, physically because your muscles are not used to it- but also tiring as it takes some time to get used to moving differently. However, after some time working on this, you’ll find your movements changing automatically, and it will become second nature. Be prepared that it will take some time. But together with working on your strength and flexibility, you will slowly but surely start seeing results. Before you even know it, you will have a massively improved posture that will give you multiple health benefits. 
Sources: American Chiropractic Association