Norman Spinrad comments on creating the right voice for your story in his essay Building a Starfaring Age:

“But how to convey the consciousness of my Second Starfaring Age Void Captain’s attempts to explain his actions to himself in his diary?

How else?

Through language. Through his language, not my own.

This, of course, is what a lot of fiction tries to do a lot of the time, tell the story in a prose that mirrors the style of the viewpoint character’s consciousness. It can be as basic as having Quakers think in thee and thou and street thugs in crude unprintables, as dumb as a long, boring dialect joke or as subtle as Flowers for Algernon or as raygun-blasting sheer powerful as William Burroughs.

This is ordinarly a matter of writing talent and perhaps the current evolutionary state of one’s craft; this is the art of it, over which you have little volitional control. You either find the voice you need for the story or you go write something else until you do.

In the case of The Void Captain’s Tale, it took me about ten years to find the form and voice for the story I wanted to tell, so don’t get discouraged by concepts beyond your current ability to handle. Let them age a bit in your mental wine cellar.”

In a normal context, writers probably wouldn’t associate voice with form, as the two are often defined differently. But I like that Spinrad uses the terms interchangeably. I also like how he ties voice and form to world-building, as this is something in my own work I’ve found important.

For the three novels I’ve got planned, I’ve spent about five years on the world-building process. My first impetus to create this world started around 2000. Ever since then I’ve slowly been brewing the details. Back then, I didn’t even know how to write/tell a story. I knew how to write, but had no idea how stories were structured, or how one went about creating something anyone else would bother to read. Knowing that I didn’t know what I was doing, I simply began aggregating details and pushed the plan for actual writing off into the future.

Some writers may call this a mistake, because I wasn’t, “getting all the bad ideas out by simply writing.” But as Spinrad says, “You either find the voice you need for the story or you go write something else until you do.” I found something else to do–something which was related to those same core ideas.

I started asking myself questions like, “How does the central concept or theme of the world affect its politics, religion, or the culture itself?” These were heady and difficult questions to answer, and required some time of their own for sorting out.

All of these things affect the voice, form, and themes of the story. If you don’t have all of these things worked out, my advice would be the same as Spinrad’s. Don’t get discouraged if your concepts are beyond your ability to handle. Let them age in your mental wine cellar. If I could add to that, I’d say that there are plenty of other things to focus on in your worldbuilding to keep you busy while you figure out the voice and form of your story.