Take 15 minutes when you can to gentle strengthen your postural muscles. Standing / sitting up straight is tiring, and the smaller stabilising muscles tend to fatigue, so build some gentle strength with these movements. Repeat regularly for better results.
Got 5 mins? Get a few practical tips you can take into your daily life to help improve your posture – from how to hold you phone, to how to sit at your desk.
The first step in improving your posture is noticing. Noticing when and how you slump and slouch, and paying attention without judgement. First notice, then the change will come.