How to Choose Which Story Idea to Write

Being a writer is awesome. Our minds are filled with complex world and ideas. We create characters out of nothing and invent new languages, sciences, magics, and creatures. We build cities and kingdoms with our words and send readers on journeys through countless rollercoasters of plots. It's awesome!
But you know what's not awesome? Having all of this in your head and being unable to sort it out. Having dozens upon dozens of story ideas and feeling completely stuck because you can't choose which one to work on.
I've struggled with this. You've probably struggled with this. And if you haven't, you probably will some day.
In fact, "Which project should I work on?" is probably one of the most common questions I get from you guys, which is why I ultimately decided a post would be better than answering all of you individually.
I personally don't like this question simply because I think writers stress about their ideas way too much (but we'll get to that later). The basics of choosing which project you work on come down to three things: where the plot is at, where the characters are at, and where you are at.

1. Where is the story? When looking at multiple projects, first focus on where you are development-wise. Which idea is most developed? If you have a project with a solid world and most of the plot sorted out, you may want to focus on that rather than your other idea with a solid world but no plot sorted out. The plot, of course, is the most important part of the book. So take a look at all of the ideas in your head and make a note of the ones you have plotted out the most. Imagine your ideas are like fish and you have to choose one to catch. The little fish are your early ideas (you have a great concept, but no real plot of characters) and the bigger fish are your stronger ideas (you have a great concept as well as a thought-out plot or at least some plot ideas). When fishing, you want the biggest fish. This is the same when choosing an idea to work on!

2. Where are the characters? Aside from plot, characters are the most important part of a book. So when faced with choosing between multiple ideas, take a look at the characters in each idea. How many characters have you planned? Do they all have names? Do they have purposes? Do they even exist? Again, it's good to aim for the idea with the most development. So if you have an idea with no characters yet, let that sit and maybe choose a different project with more developed characters.

3. Where are you? This is easily the most important part about choosing which project to work on, because every single person in the world is different. You might have a bunch of developed ideas in your head, or you might have a bunch of non-developed ideas in your head. Maybe you have one idea with a great story world and no characters, and another idea with no story world and great characters. Or maybe you've already stopped and started a lot of different projects, and now you can't decide which one to truly focus on. (This tends to be my struggle, as I have stopped and started a lot of projects over the years.) The most important thing to look at now is yourself. What do you want to write? Which of your ideas stands out to you the most?
Because let's be honest: it's so easy to let future worries cloud our decision-making. For example, I used to solely focus on Unperfected because I thought I could only choose one project at a time. I thought I needed to get one book done and published and worry about the rest later.

But that's not true! For all of you writers out there worrying about only choosing one project to work on at a time: don't. You are your own writer. Work on the project you want to work on when you want to work on it. Want to write your big project? Go for it. Sudden urge to start a brand new story? Do it. Don't want to write and instead want to just brainstorm a completely different project? Have fun!
I tend to focus on my bigger project (Unperfected) a lot because it is the most developed idea I have. I know the plot, the characters, the world--everything. But sometimes writing it becomes boring and draining because I've been working on it for so long. So when that's the case, I turn to my other less developed projects and work on those. And that's great!

I can't tell you which project you should work on. No one can! It's something that you as a writer need to decide for yourself without pressure from anyone or anything around you.
Writing is fun, and it should be fun. So stop stressing so much about which project you should focus on and instead enjoy taking time for as many as you want.