"How the hell am I going to bring all of these ideas together?!"
If you're a writer of science fiction and/or fantasy, I'm sure you've experienced this dilemma. A mountain of really cool ideas are sitting in your head, waiting for their opportunity to be brought into existence. But, when you sit down and try to compile the list of seemingly endless variables, you find yourself unsure if it'll all fit together. Ugh.
To be the creator of an entire fictional universe is not an easy task, yet here we are, notes in hand, trying our best to mash it all into one cohesive story-line. I wish I could tell you there's an easy way to do this, but I can't. There is no easy way to world-build. It's way more likely than not, you're going to hit a stumbling block or two trying to make it all work as one. Luckily for us, there are some 'best practices' you can employ to minimize those blockades.
1 - Concretize it
What exactly do I mean by 'concretize it' you may ask? Well, I'll tell you. Just like a concrete mixer, the ingredients that threatens to create a solid foundation will never solidify until it's all poured out and allowed to be in the light. So, 'concretize it' means you write it down, talk about it, put in on your blog, draw it, etc. It's all a way to get those ideas out of your head and into a form that's solid. You can even use index cards with specifics that pertain to your magic systems, alien races, high-tech weapons, etc.
The point is, those thoughts are no longer swimming in your brain as a collection of ideas or a jumble of brilliant flashes that you've memorized. Once the ideas are out of your head, you'll find yourself seeing the holes in the concepts and start the work of filling in the blanks that'll give your universe a strong foundation.
There's something special about taking your thoughts and putting them down that allows your rational mind an opportunity to review what your creative mind came up with. You have to provide the entire YOU a chance to work on those ideas, not keep it in the darkness of your imaginings.
2 - Collaborate
Yep, you introverts may actually have to talk to other people, preferably writers, about your vast array of alien races that want to invade Earth all at once. Why? Because it works.
Don't approach such a session looking to defend your ideas. Your collaborators aren't there to poke holes in the ideas, but to point out both the weaknesses and the strengths of the concepts. The process works because, just like your readers, your collaborators will see and question the things you don't see or recognize as weaknesses in your story. Sometimes (for me at least) the creator can't see the flaws in their creations. So, bouncing the ideas off the brains of others is always helpful. If you can find a writing or critique group that you enjoy, take part and explore your brilliant fictional world with a few fellow creators.
By the way, 99.99% of the time, other writers aren't interested in stealing your ideas. We writers tend to have a crap-ton of our own thoughts to contend with. Your story would be just another grain of sand on the beach.
3 - Practical Application
Okay, you've created a world, just like Earth, but it's inhabited by psychic monkeys that eat shoes and they exist right alongside humans. Do you really think history would develop exactly like it has so far on Earth? No ripples that'll alter our current existence? That's not reasonable. There are consequences to having such a creature around and their existence would have serious impact on how our world has evolved.
Let's look at something not as extreme as my psychic monkeys, just an idea that aliens existed amongst humans for centuries. Why haven't they intervened in all of the atrocities that have occurred on Earth? If they are indeed as advanced as the theory would imply, why did they sit by and do nothing during WWII? Rowandan genocide? Or, why do nothing during any of the hosts of horrors humans inflict on other humans? What does that say about them?
See what I mean? The world would not have existed exactly as it has if that were the case. And, if it did, that would make those aliens a bunch of callous assholes to just watch so much death and simply walk away in the face of it. Therefore, the more fantastical your ideas, the more the world would be forced to change to reflect those ideas.
Nothing on Earth exists within a vacuum.
Many blessings! And remember, NO EXCUSES. JUST WRITE.