Practicing good posture does not have to include walking around the house with books on your head.

Wear a back brace or waist trainer:

This is a simple and instant solution to a bad habit of hunching your back. Wearing a back brace or waist trainer will force you to sit or stand upright. This should not feel extremely uncomfortable. If you are uncomfortable you may be wearing the trainer or brace too tight. Invest in a back brace or waist trainer and wear it for a few hours a day. Pick a time where you typically have poor posture. If you tend to hunch your back while sitting, wear a back brace or waist trainer while sitting. Even when you take the trainer or brace off you will be more conscious of practicing good posture. Think of the brace or trainer as a jumpstart to perfect posture.

Invest in an ergonomic furniture:

If you're hunched over your desk right now you may want to read this. Sitting in a poorly constructed chair may be the cause of your poor posture. Change your office chair to an ergonomic chair. Ergonomic chairs from Beverly Hills Chairs adjust to your comfort level and will keep your back supported while working. You can also switch to an ActiveErgo sit to stand desk. Sitting in a chair all day will weaken your posture over time. However, having the ability to lift your desk and continue to work while standing may enhance your posture.

Strengthen your abdominal and lower back muscles:

Without abdominal and lower back muscles humans would not be able to support their upper bodies. Therefore, in order for your posture to go from mediocre to great, you should do core exercises. Try planking exercises. Planking will exercise your abdominal and lower back muscles simultaneously. You should aim to do at least one planking circuit (hyperlink) at the beginning or end of every day. Enhancing these muscles will make sitting and standing straight less of a struggle.