One of the most useful skills you can acquire is how to learn from others. Sure, there are teachers who will specifically sit you down and educate you, but there is so much knowledge out there in the world beyond them.
You can learn so very much by reading books and journals. You get a feel for what styles resonate with you, words and phrases that produce certain reactions, how you can interweave ideas, and so many skills. You can also learn from reading the random words surrounding you, even on a piece of paper in a buffet.
Another great source to learn from is yourself. More accurately, perhaps, is your past self. If you have written before, return to that writing. Read it with fresh eyes. Read it as though it was foreign (and if it has been long enough, it will be foreign to you). Analyze it like you would any other writing. "Wow, that was really good" for the sentences that moved you. "Meh, could have been better" for the so-so ones.
You have a unique relationship with yourself. Although your old works lose familiarity, they are still yours. You know that you came up with and created all of those words, in that order. They are proof positive that you have accomplished great things in the past. And your current self is proof-positive that you can recognize the flaws or lackings in your past writing, which means you have the wherewithal to correct and improve them.
Learn from yourself. You are a valuable resource.