My advice would be write as often as possible and read as often as possible. I find if I am reading my favorite authors, I can note things they do in their writing style and use them the next time I write a chapter. I also put anywhere from 2,200 to 3,000 words in each chapter, forcing myself to add and write more if it is too short. My cap has grown bigger through the years, but has recently settled in this area. I used to write only around 1,750 per chapter and then gradually made my limit bigger as I wrote more to challenge myself to write better.

I would also avoid clichés and fast storylines. The more fluff the better. I would go back and look through the Harry Potter books or the recent Rick Riordan books for reference of how to add good fluff. You can have a general idea of what you want the plot to be, but you need fillers for the space in between. You need subplots, like Hermione's SPEW project, or the time Hagrid got a dragon, or the Death Day Party, or the Quidditch game throughout the series. There are so many subplots and they take up time so the story becomes more than just about the main issue. This will also test you as an author if you can fill in the spaces.

I still have a lot of trouble with it, trust me. I still tend to rush plots and storylines. I feel like I rush through things, so plot points I originally wanted are left out.

You won't be amazing when you first start out, trust me on that. Go ahead and reread The Undercover Spy after reading my most recent book and compare how much better I've gotten and how much my writing style has grown. I'm still in awe that a story with so many mistakes is so popular, but you can see that my new stuff is greatly improved from that. If you practice, you will get better.

Watching a lot of good TV helps too. When I see character development, it gives me ideas and helps me realize how to write a certain character's story that I was confused about before.

Also, write around your strengths. I am awful at a book only about romance because there are no real villains and I have practically no experience in the area. However, superheroes have tangible villains and the romance can be only a subplot, making it a lot nicer for my tastes. Plus, it is much easier to get out of writers block my making a villain jump out of nowhere to attack, while romance novels can't really have a random event like that without hugely affecting the plot in some way.

I am also bad at writing action, so I am able to find ways to avoid it by making the character I'm following occupied with something else, like taunting the bad guy or saving pedestrians, anything but fighting. (I don't know if any of y'all noticed that until now, haha)

In summary, give yourself word count limits, add fluff and subplots, read, watch TV, and write as often as possible, and write to your strengths.

That was long, geesh.