There's a certain type of question which comes up regularly over at AW and an area designed for them. They go in the Basic Writing Questions section which might sound a little off-putting to non-writers, but it's really not. Every writer is a newbie at some point and every writer asks questions that might seem to have an obvious answer to more experienced writers. Nothing wrong with any of this in the slightest.
The interesting thing about a hell of a lot of these questions is the same answer can be given to just about all of them.
It depends on the story.
Should I have a prologue? Can I write in first person past tense? Is it OK to mention Facebook and Youtube or will it date my book in a few years when we're all using something else? Am I allowed to swear? Will an agent reject me if I use a racist term?
It depends on the story. Say it with me, people. It all depends on the story. Every book (which means every story) is different. Or should be unless you're Dan Brown, but that's a subject for another day. Plenty of writers have themes they write about repeatedly and as long as you're not using the same story to write about those themes, I don't see much wrong with that. Plenty of writers - including me - have writing habits they need to stick to. Again, nowt wrong with that. What matters is being aware of each story as its own tale and that means everything a writer does, every choice they make and so on all depends on that story. Some need a prologue and some definitely don't. Some are begging to be told in first past or present; others are all about third. Some odd ones are even about second person future tense but we won't go there just yet.
I sometimes get the impression new writers think there's some magic formula to writing, some special trick which results in an immediate bestseller. They think it's do with following all the rules to the letter or having a set number of scenes or length of chapter. Rules are definitely to be learned as are the reasons for breaking them, but the rest of it? The only trick to writing, if you want to call it that, comes down to two things.
1. Having a damn good story.
2. Writing that damn good story.
Everything else is just noise.