If you are invited to someone’s place always take something along. Could be as simple as a bottle of wine or as elaborate as a home made cake.
Say thank you, please and sorry when needed. Nothing wrong in being polite.
Help someone with the door if they have their hands full when entering a mall, shop, restaurant etc.
When someone asks you for stock/financial advice tell them you don’t know better than them! Avoid stock tips, you can ruin someone’s life.
When someone is talking, really listen. Look into their eyes time to time and nod. Does not matter if it’s a guy or a girl
Give credit where credit is due. Take responsibility if things don’t work out
Blessings