Whats a good way to maintain good posture?

Thanks:]

Sit on chairs that force you to sit properly, don't slouch.

When you sit try and sit with your back flush to the chair, not slouched, this is harder to accomplish on a couch or lounge chair. Stand up straight, not rigid but straight, although most of us look like were walking straight but most of us are not.

Practice??
Yeahh, not helpful.

Wear a corset.