Talk it with a bottle of salt ;)
Learn to do by doing.
You learn to cook by cooking. Learn to build houses by building. There is a certain amount of 'book learning' but it can only take you so far. Reading a book on making roses out of radishes is great, but you need to practice, you need to do.
You can read all the books you want, take all the courses and classes and seminars you want, but you have to write to learn to write.
Learn to accept that there are times with an idea, though or project will not make it.
Certain people will tell you that I have far too many ideas and will never be able to execute on them on. Others will tell you that I hardly ever have any. The difference? The first group is my sounding board, they hear everything. Well, everything that makes it past the internal hurdles. The second group only hear the ideas that make it through all the hurdles. Some just aren't realistic. Period.
If you think up 10 ideas a day, 5 of them will be ideas that even you consider silly. Taking a safari to Australia to paint polka dots on Bears? Not viable. Starting a project when you give away money to help people, viable but probably not in your best interest ;)
Point it, don't be afraid to think up things. Hundreds of things, thousands of things. GadjillionBillions of things. Statistics alone will guarantee that at least one of them will be a good idea.
But learn to accept that not all of them are.
Also, learn to accept that sometimes, no matter how much of your blood, sweat, and tears you have invested… it isn't going to happen. Not saying it's not a good idea. It might just be ahead of it's time, the wrong audience, the wrong way around…. a thousand different things. If it's dragging you down and keeping you from coming up with ideas.. put it aside. Look at it again tomorrow, next Thursday, a week from Saturday, during the next full moon. Give it time and distance. Get a fresh perspective. Chances are you will see what's off and be able to fix it.
If so, then go at it. If not, wait until Christmas.
This isn't one of those 'accept that you will make mistakes' things. I mean you will, but it's more of a 'take chances'. Some things won't work. I have stories that I've tried to get out in every possible format. Audio, video, comic, prose, whatever I could think of. Not all of them work. I (and most writers) have a notebook FULL of ideas that didn't work. Why? Who knows. Sometimes they didn't mesh, others they just didn't feel right on paper.
Try new things. See what happens when you put an alien from the planer Mithar into your 1940s hard boiled detective story. Maybe it won't work, but maybe it will and you realize that is what was missing from the story and it becomes about something more than just a killer that dresses his victims up like dolls.
Stop listening to people.
Including me. I never graduated from college. Hell, I never started. So when I started getting work in the tech field (I taught myself) I had a different perspective from everyone that had gone to school and gotten a formal education. They all thought in a similar manner. Rigid and only semi-flexible. It was very much an attitude of 'This is how we do it because this is how it's always been done.'.
The writing world is very like that. (Not the rigid part) You will have countless people telling you that you have to follow this rule or that one. That you can't mix magic and futuristic tech. That author John John did that already and it didn't work and he's a famous author so what makes you think you can.
And my favorite, that you will never be the next great novelist or that you probably won't succeed.
Ignore them. Write what you want to write. Tell the stories that are in your head. Keep doing it. If you are doing it to get rich however, stop. Do it because it excites you, because you will go mad if you don't get them out of your head. Question everything. Challenge everything. New rules are made by breaking the old ones. Will you be the one that changes everything? Maybe. Won't know unless you try.