A bit on genre and style.
I would imagine action and adventure stories have excited teenage boys (and girls) for all of human history. I would daresay this is the reason online games use action and adventure narratives for their storylines. The thing that worries me, however, is how influential online games and action films are when it comes to creative writing. It’s great for a writer to know and love the genre they write, but there is a skill in using other genres to help flavour the prose. Films and online games are fun and easy ways to enjoy stories, but for our creative work it is useful to investigate other styles. Here is a list I’ve made.

• Short story
• Poetry
• Novella
• Novel
• Song
• Micro-fiction
• Short film
• Feature-length film
• Online game
• Myth (e.g. Greek myths, Gnostic scriptures, fairy tales)
• Verse novel (a novel written in verse/poetry) 
• Plays

Reading a play, for instance, can be a great lesson in dialogue writing. In playwriting, a lot has to be communicated through speech. Also, we should think about what is NOT said. Some stories and films are excellent examples of powerful subtext. Can you think of one?

The great thing about writing compared to screen is that you can show the audience so much of how the characters are feeling, what their private thoughts are, how they lie, how they feel compared to how they react.

A bit on structure.
It could be helpful to open up a few novels and look at how they format the text.

• Do they use dialogue tags?
• Are the paragraphs long or short?
• How often do they start a new section or new chapter?
• Is the book divided into parts?
• Is the whole thing written from one character’s point of view or is it written form multiple points of view?