If you want others to act positively, then you must start by acting positively. This isn’t just a sometimes thing. You need to be consistently positive – be optimistic, smile, show good body language, look others in the eyes, use verbal encouragement, and speak with energy.
If you have something going on in your personal life, don’t bring it to work (and vice versa). Don’t be moody. When you’re moody, those around you never know what to expect. If they’re walking on eggshells around you then you will lose touch with them. They will begin to not share what’s on their mind with you for fear of catching you at the wrong time.
Practice what you preach (positivity), otherwise they are just empty words. Those around you will see your hypocrisy and resist your message if they feel that it is not congruent with your actions.