2) Never sell a creepy relationship as romantic. If you want to be romantic, leave out the stalking, the possessiveness, the over-the-top jealousy. But, if you must have a relationship in your story that's going to be creepy, make sure everyone knows it's supposed to be. Call out that creeper and don't let them get away with being so creepy!
3) Don't be too nervous to try reading something more difficult, or an old classic. Also, never be too pretentious to read children's books. Read everything. Read inside and out of your favorite genre. It'll all help you in different ways.
4) "Show don't tell." You know what this means in writing, I don't need to tell you again. Or show you again. Or go off on a rant again. This is a life rule: actions speak louder than words. Make sure your words and actions line up. Also, this can be a good way to give a character whose supposed to be annoying a real flaw, if you have trouble with things like that.
5) If you struggle in a writing class, don't lose hope. This isn't where it's determined whether or not you have the talent to write. Creative writing classes can be fun and useful for a lot of people, but they're definitely not for everyone. Writing is such a personal journey, there's no one size fits all method for learning how.
6) There may not be a method of learning that will work for every single person, but there are two tips that certainly will. Don't forget them! Read as much as you can. Write as much as you can. These are your golden rules, and the only ones you really need!
Good luck, and happy writing!