I love having a fantastic imagination. And being an author allows me to dive deep into the aspects of the world that surrounds us.
Say what you will, but nothing is better to me than creating your own reality.
In actual aspect, I use my roleplaying background a lot when I write. You have to consider every side of the story and your characters, make sure the atmosphere fits what you like to write. Hope you’ve caught all your errors, that everything fits the tools you've given them.
How much do you reveal to the audience? How much do you hide?
One aspect I know I need improvement in is describing the world. How do you describe the color blue to a blind man? How do I get you to see the hairy orc, drool dripping through his fangs standing next to an ant the size of a man. How do I show them conversing with different voices? How do you show their different voices?
There are a million different ways, and none of them work for everyone, though all of them work for someone.
There's outlining, planning, setting up your planned chapters, knowing where you want the plot to go. Mapping all the characters, keeping it all in order, and saving your characters(or abandoning them) to bring it all to a close.
There are thousands of formulas and programs available to help.
Genre makes a difference as well. A space opera needs to feel like a space opera. Steampunk needs tons of steam powered machines everywhere. Cyberpunk is going to be shrouded by the background of technology. If you're writing a love story that takes place on a beach.
Make sure once you have an environment, you stick to it!
If your characters have no growth, no one is going to care about them.
There needs to be hardship, struggle, choices that make them into a changed person.
I am a pantser. I never really know what's coming next in my stories. I tried planning a whole book once, it ended up 40 pages shorter than I wanted. It took a lot of development and editing to get it where it is, and while it was fun, I couldn't really write anything else until I moved on. Some people live in the madness of editing, I am not one of these people.
I write a chapter at a time, looking at the world around my characters and considering it dynamic. There are random encounters, strange people, and a million little things I don't think I could plan.
And yet some people are the exact opposite. They plan it all from beginning to end, covering every meticulous detail, one step at a time.
The point is, no matter what you do, your going to develop your own style. Have fun with it, look to constantly learn. Remember no one knows it all, even those at the top.
As for keeping the character voices and identities in order, you need to keep them grounded in what they are. A little girl shouldn't be selling weed to high school kids, unless they're meant to and it fits the story. Your robots should follow logic protocols, unless you have a reason for them not to. A hive mind will move in unity, unless you give them a reason not to. And a man’s heart isn't always through his stomach.
Treat them like real people, because they are. If someone close to them dies, they’re going to go through the stages of grief(psychopaths excluded).
I admit I act mine out. My friends look at me like I'm insane when I start asking them about insane situations.
Draw on the people and loved ones that surround you, even as you slowly drive them insane.