The most important thing to remember about your behavior is to stay true to yourself. Avoid doing something just because it'll make you look good in someone else's eyes, and stick to what you know is right for you.
If you've been put on the spot and asked to do something that you don't feel comfortable with, don't be afraid to stand your ground. It shows that you are strong enough to make your own decisions.
You can stop being a people-pleaser, but not by changing who you are. Instead, be true to yourself, and people will respect you for it.