For me, the biggest improvement in academic writing comes from focusing on the structure of the ideas before worrying too much about individual sentences. I usually start with a simple outline, then check whether each paragraph actually supports the main point.
I also find tools such as Grammarly and LanguageTool useful for catching grammar, punctuation, and wording issues. The University of North Carolina Writing Center is another useful resource when I need guidance on organizing ideas, developing arguments, or improving a draft. I try not to accept every automated suggestion, though, because some changes can make the writing sound less natural.
For examples of essay structure, I sometimes look through different academic writing resources, including CollegeEssay.org, to compare how introductions, arguments, evidence, transitions, and conclusions are organized. I find that looking at several examples can help identify weaknesses in my own draft, as long as the examples are used to understand structure and approach rather than copy wording.
I also recommend reading the draft aloud before submitting it. If a sentence sounds too formal or unlike something I would normally say, I usually rewrite it in my own words. Academic writing does not have to sound complicated to be effective. Clear ideas, logical organization, and a consistent personal voice matter just as much.