Publishing is a very strange world in which you're learning as well as actually doing at the same time. Sometimes this will backfire, but in my experience, learn as you go, fix later.
The biggest thing to tackle is 100% the world you're writing in. There's a thousand different ways to go, and each has it's own nuances.
Now, I'm not an English Teacher. I'm not someone who has gone to school for this. I don't offer paid for classes. I can only tell you my experiences and what I've learned after writing and publishing 15+ books.
Take my advice with a grain of salt, and preferably a margarita.
Modern Day with Magic
This category I'd lump in the most popular of genres - Urban Fantasy and Paranormal. I always say if you're looking into jump into magic, this is a really safe place to start.
The benefits of starting in Modern Day is that you don't have to really develop too much in the world building part. Of course some things would change. You're going to have people and creatures that aren't in our modern day, and that would change the culture of the world.
But there will be familiar things. Starbucks, clothing, all that will still pretty much be the exact same thing you'd expect.
Some things to think about -
Most people will expect you to do more than just "toss in some magic". You want to create multi-dimensional worlds in your writing. You want to make people think, and for it to stay with them for a long time to come. This includes creating more than just "it's today, but with witches". Make it more. Add in culture, and history, and theoretical studies that all combine into something wonderful.
Just because it's modern, doesn't mean you don't have to research. Where did your creatures come from? How did they end up in the world? How far can you push it?
There's a 101 books about Science Fiction, and honestly, it's not something that I've researched a TON yet.
I'm not going to wax on about this one, there's more people who are certainly better qualified to talk about this. The number one thing I've seen as complaints is people putting science fiction stories out without the research in the slightest. Do your research. Science Fiction above ALL OTHERS requires explanations for the choices you make.
Keep it in mind.
Historical (with or without magic)
HISTORICAL. Slightly more my wheel house to talk about haha.
If there's anything I can suggest with this, it's RESEARCH. RESEARCH. RESEARCH. And if you haven't researched yourself into an early grave, then you haven't researched enough.
I learned this the hard way (as I tend to do). With the Otherworld series, I didn't set a particular time or era. It's medieval, but it could be 1400s or 1700s. By not tacking this down, I actually hurt the series quite a bit.
Of course, you do everything you can to fix it, but this is highly important to the production and continued enjoyment of your series.
Things to consider -
What time period is this set in? Within 50 years, history changes a lot.
What clothing did they wear?
What kind of houses were there?
Were there any specific historical figures you could reference?
This probably seems a little bit like "Duh", but you'd be surprised how much you forget when you start jumping into a story.
Even I had a ridiculous amount of research books stacked up on my writing desk to make sure that I have all the information possible! And you'll still forget things. So map it out first make sure you have all the details in your head, and then fact check when you're finished.
Completely new world
Original worlds are.... hard. Like really really hard. But they are HIGHLY rewarding when you get them right.
There's so many possibilities that it's easy to write yourself into a corner, or worse, make it almost impossible to continue writing the story because you're stuck on one tiny thing in the religion of a small sect of people that only show up on a couple pages (*ahem*).
So my advice is very similar to a lot of fantasy authors. Keep it simple. Keep it clean. And don't make something so rigid and structured that you're going to end up messing up on your own writing.
You can find 101 templates out there to help get you started. My favorite is THIS ONE.
Start by fleshing out the landscape. What kind of environment is there? Is there more than one? This is where I started with Wildewyn and Bymere.
I usually start with having a map designed because A. They're important and B. They help me figure out where the hell everyone is.
After you have the environment, you move onto the culture. Most importantly, what would the ENVIRONMENT create in a culture. You aren't going to have people living in a desert kingdom wearing furs. They're going to wear light clothing, be darker skinned, live harsher lives that worries more about food and water than a country like Wildewyn which is lush and green.
Research cultures that are real and flesh out your peoples with that. It's so important to have familiar details that people can grasp onto. In Bymere, they have a ceremony similar to Holi. In Wildewyn, there's a small group of people with body modifications similar to ancient Aztec.
Familiarity is your friend above all other things.
I hope this helps at least a little bit!
I'm going to dive into a lot more detail with writing, creating, developing, publishing... Everything I can to help out other people who might be interested in getting started in this field of work.
As always, if you have any questions or topics you'd like me to cover, please comment down below!