When you greet someone, say “hello” cheerfully and smile. Look them in the eyes. Have a firm handshake. Stand up straight. Keep your head up and your shoulders pulled back. Project confidence. Project happiness.
People want to work with and be around people who are magnetic. The list above is something that can help you be magnetic, even if you don’t feel like you are. Nobody wants to be around a negative/pessimistic person with low confidence.
The other thing you want to do is try to make others feel better. If they feel great every time they leave a conversation with you, they’ll want to continue to have more conversations with you. Be uplifting, but don’t be a pushover. Be agreeable, but not too agreeable. Don’t be afraid to speak your mind/tell the truth, but do it in a constructive way. Have a positive attitude and they’ll know that any criticism is coming from a good place (you trying to help).