Tilt your car’s rear view mirror up a bit higher than what’s comfortable… it’ll force you to straighten your posture whenever you go to look into it.
Put a sticky note in the center of one of your commonly used home mirrors that says a message you want to internalize… e.g. “You look great.” or “Be here.” or “Life is too short.”
Buy a chair that doesn’t have a back, where the seat is angled down slightly and there’s a pad for your knees… whenever you sit to work, slouching and hunching will no longer be options.
Add labels to the timers on your phone to remind you of the “real” reason behind it going off. e.g. Instead of a 6:00am alarm, add a label that says, “The Only ‘You’ Time Of The Day” or a 5:00pm alarm that says, “Family Time Starts Now.”
Get a dog. You will never have a better accountability system to go for walks. And walks make just about everything better almost every time you take them.
The best way to make long term changes is with enough short term feedback. Set yourself up for success by making your environment better by design.