One of the things I've learned since the new term began is my writing has definitely improved. More than just improved, I know why I write what I write.
I don't mean the content (I already knew that one!). Rather, I understand the writing process better from start to finish. I understand why certain sentences need to be rephrased. I understand logically what I used to understand intuitively.
For example, many writers struggle with the passive voice. To say something like "I was going..." is so much weaker than the active "I went." It may be necessary for some dialogue, but that should be the only time. Why? The reason is because the passive voice is the verbal equivalent to a whimpering weakling. Weaklings don't win. They don't have a major impact. When writing, it is important to maximize the impact of one's words. Thus, we should always use the active voice.
Now, I knew this intuitively. I always revise with this in mind, however I didn't know what the active voice was explicitly. I know - I should have. Well, that's water under the bridge. The good news is I know writing rules now like the back of my hand. I now look more intentionally for errors in writing whereas before I waited for my intuition to tell me something was weird. It's pretty clear how much more effective I am now versus then.