Learning to draw better comes through trial and error. You can only get so far with your own skills. You can follow tutorials, something I recommend anytime. But after that you’re bound to start doing courses. So where do you go? And what should you avoid? Or even, what do you prefer?
There are many amazing artists out there, and some of them use YouTube as a platform to teach. So, if you are looking to learn something new, or want to understand different approaches to the same subject a bit better? These artists are a great place to start. They will help you getting a better understanding of the work field, different techniques and approaches, and different materials and tools.
Creating a creature from scratch sounds wonderful. You wake up from a dream and have this wonderful impression of a great beast. But when you are drawing from imagination, it’s nothing like that mighty beast you saw in your dreams. Why is that?
It has little to do with your skills in art, the explanation is more complex and interesting than that.