I spent some time thinking about this recently. It's kind of frustrating. It seems that most of the advice out there on posture is about why sitting up straight is good for you. There are also all these diagrams that show you how your back, shoulders should look like. But as crazy as it sounds, I just can't remember to consistently sit up straight.
For the past 15 minutes, I've been sitting with a book behind my back. It's pressed up against the back of my chair - so long as I don't slouch. This has worked for the past 15 minutes. Not sure how annoying this would get day in and day out. Has anyone tried something like this?
What else might be a good way to encourage proper posture?
EDIT: I've found placing the book between my back and chair to be pretty effective, but only during the times I remember to put a book there. :(