Okey dokey here we go…
I’ve done this before and I am here to impart knowledge on you that I really wished I knew when I started something like this…
1: Have extensive/rich lore. An explanation of the creation of your world/events that have happened before and godly figures REAALLY boosts the fantasy of your world. People looooove lore, so make sure you give them it. Make sure it has some connection and relevance to the current story. Example, the main character is descended from a species of giant that conquered some sort of war. Or, a similar event that happened back then, is happening now, almost like history is repeating itself, or the same adversary has been alive and has been causing problems since then.
2: Names. Names are really hard. If you’re running out of ideas, take the name of someone in your life and change it around to fit your story and it’s language. I have a friend named Callum, and I took and changed that name to Calos. It’s a pretty good system.
3. Don’t bother with what others have done. This does not mean “don’t read other people’s stuff because you could end up copying it.” No, it means write what you want to write, and don’t pay attention to what has brought others success. You shouldn’t add romance if you’re not a good romance writer just because other successful fantasies have them. Doesn’t matter if people have done it, do it your way. Don’t feel like you have to give up on a character or a place because it’s been done before. There have been times where I felt like I had to change an entire character simply because “people have used wizards many times before.” It doesn’t matter unless you go too far and basically copy what others have done. Make sure you give said character something of your own, like a unique ability or trait. For example, in Harry Potter, wizards need to say incantations to cast a spell. You could have them have to touch a gem or something to awaken their ability. As long as it’s interesting, limits the character’s power, and is for the most part original.
5. Characters. Make sure your characters are well crafted and balanced. If you make your character too powerful, people will call them a Mary Sue and such. If you make them too weak, people will be disappointed. If your character has some immense power, give them some sort of plight that limits said power. Example: this character can control minds, but does not know how, or faints when they do, or becomes drained. Make sure that this doesn’t go too far so that when the final battle comes, they can’t fight. Make sure they have a psychological/internal conflict as well. The character could have a fear of loss, and is afraid to leave their friends behind to fight their adversary or something. Or the character is easily tempted. Something like that really helps beef up your character and make them more human to the audience, which will allow them to resonate with the character and immerse them in the story.
That’s all I got for you now. Make sure you have good world-building and have interesting locations/characters. Good luck!