A general piece of advice is to not take any advice! At least not fully. It’s probably the same with all the arts, but I’ve noticed that those who teach creative writing can tend to be rather dogmatic about what works and what doesn’t. Often, they learnt their approach and rules from school, or an MA course or other writers. What’s helped me most – both in my writing and my teaching – is to try all kinds of workshops; read all kinds of advice books; talk to all kinds of writers. I’ve found some perhaps surprising things. For example, the best craft workshop I ever did was taken by commercial writers and I don’t even like commercial writing. Similarly, one of the least inspiring or useful workshops I took was taken by someone with an MA in creative writing, who teaches at a university (but hasn’t published very much).
Taking the wrong advice fully on board early on your journey might cost you years of wasted effort. For example, there is a strong school of thought that writing equals tons of re-writing; that your first draft will inevitably be a shitty draft. This is often taught as gospel; that there is no other way to produce great writing. But there is another way, well, other ways. And the shitty first draft philosophy can, for some writers, be totally stultifying to creativity. You have to find what works for you; but you also have to learn the craft. So I guess my overall advice – and don’t take it fully on board! – is that while you’re learning the craft, keep an open mind about what is going to work best for you in terms of releasing creativity. Which means learning about yourself at the same time, of course.