That's the gist of it. Write more. Keep writing. Write until you have no more ideas left in your head, find some more, and write again.
The purpose of this exercise is to help you become more aware of the words you use, and to develop your "voice" as an author. It helps you build upon your writing skills, no matter how poor or strong they are. But what about the people who've been doing this for ten years?
I have another piece of advice: drop the "aspiring" part of your title.
Stop dreaming, and start making things happen. I don't necessarily mean publish a book by yourself right away, or submit a book to a publisher. Start with something smaller. Try submitting a short story, or a poem, to a literary agent. Pitch an article to a magazine or newspaper. Do something to get your name out there, and edit your online bios.
Let's look at it this way - you look a lot more professional if you say, for example, "Mum of three, working on my first novel" than "Mum of three, aspiring author". One says you're doing something, the other says you're thinking of doing something. Similarly, "Aspiring author, 16, student" says a lot less about you than "Young author, working on a book, 16, student".
Do you see the difference, yet?
If you want people to take you seriously, start presenting yourself seriously. The amount of people who want to support young authors and writing mums is astonishing. Yes, you need to keep writing. However, by living your dream instead of just wishing for it, you're much more likely to do something you can be proud of.
When I dropped the word "aspiring", I found the courage to set up a website and apply for a writing job (which I got.) A year later, I published my first book, and wrote an article for a magazine about it. It's all mindset and confidence. I improved as a writer by that simple act of identifying as one now.