I really need help with my sense of humour?

you know when you have good friends and you joke around with them and tease them about stuff? well im always afraid of teasing people in a nice kind of way cause i feel like their gunna think im wierd, but the key of being friendly is having a sense of humour and bein able to joke around with people and make fun of friends for stuff....any suggestions on when to do mess around and how to develop an easygoing sense of humour with people?