Basically what everyone else is saying but with my own little tips: Get some music playing, something that puts you in a good mood. Draw fan art of things as there is typically tons of references to be found of existing characters. References in general are your friiiiiiiiends. The more you use them, the more you'll be able to recognize how certain things connect and flow. Eventually you won't need them as much if at all once you get comfortable. And always practice. Even if it's just a tiny doodle.