I'm writing a story to set in a parallel world. My characters will travel around this world for a search. They'll visit many place but I don't know how fix these places on a map. Is better to fix places before the writing or during the writing? If I know before the world, I can choose their itinerary, but if the places are not fixed, I can change them... I'm so confused. Can you help me?
When I first started my world, I made it before I wrote. Then I realized that I wanted her to visit certain cities and places, and the way I placed them on the map before just didn't work anymore. So I redid the map. You could plan your story first (where you want your MC to go) then draw your map. But if its too hard for you to write without a geological reference, you can always draw your map first and change it as the story goes along.
Writing is dynamic, and the various planning documents involved in writing all change during the writing process. Something new about a character will change the plot, or some new plot element will change the setting, or a new, necessary part of the setting changes a character. I find myself constantly going back and revising all aspects of the plans for a WIP while writing the latest draft, and even before. But one interesting angle is alternative realities. I know a midlist published writer who specializes in Sherlockiana but, on the side, writes alternative history novels and self-publishes them. One features the American Civil War never having happened and the US having peacefully splintered into several countries, but the novel is set in Europe and traces how the Second World War unfolds in Europe in light of those revisions of history. It's not the fantasy setting you're looking for, but you could easily revise some aspect of earlier history to make the world a fantasy-land today. It would take research and thinking, but it can be done, and has been done very well by other writers.
It might be best to build a framework for the new world--the main places and cultures and even people and significant historical events (if appropriate). Then, as you write fill in the minute details. The framework will help to make it consistent, but you could spend years fleshing out a created world to the smallest detail. Keep track and plan as you develop, especially if you hope for the first novel to become a series. What's published (put in print) can not easily be changed if you painted yourself into a corner when you want to expand the world or plan a new plot/novel.
Thank to all for your help and suggestions! I think that I need time and concentration to use your suggestions and various ideas to fix my world! I should write 10 short stories set in different places and I would like that these place could be very different among them. But I think that I should take a bit of time and to think!
I generally know from the outset what the essential properties pf my world are, because of what the story demands of the world. Those properties may require some pre-planning to make them consistent and plausible. There may be calculations involved (My main interest is hard science fiction, so realism of the environment is important to me.) Apart from the essential properties, most of the rest is window dressing, and I can construct it as the story grows. Indeed, I prefer to, as I prefer to shape stories organically as I go, rather than try to plan everything before I set pen to paper (or appendages to keys).
I try not to put too much effort into coming up with fantasy worlds as I find sitting down and trying to force inspiration causes cliched and flat settings. When it comes to maps I would personally leave them until I feel like I need one to make sense of it in my own mind and then I plot out new places as I go.
I tend to plane story, actions and places because I'm insecure and I think that during the writing many events can influence the subsequent. In this case, you'll must change a part of story and I think that it's hard. For this reason I prefer to plain before to write, also to add many details and to make everything real. I would write about fantasy places, but I would like that they can be "real and plausible".
I'd say fix the KEY places first...the dungeon at the end, the volcano in the middle...and then string the rest along, if they are small, to how you feel it will evolve.
Maybe this is a strange way of doing it but... Minecraft! Of course, it depends on what kind of world/story you are trying to make, but I sit down with the game and place blocks, building something unique. Eventually my imagination fills in the gaps left by the basic graphics and I'm left full of ideas and inspiration. What I then come up with isn't a game world, but something born from thoughts I go through as I relax and build!