As the title says, I am trying to learn how to paint better.. do you have any tips or suggestions? How did you start out?

I love painting and I love exploring it but it always frustrates me because I can never get the techniques correct, I can't wait for the paint to try so it messes up and I've never used an outline. I love expressionistic and abstract paintings but I'd also like to somehow try out realism, if it is ever possible.

What do you think? How do you paint?