I have been trying to find a way to create a galaxy map for the universe in which my battles are taking place. After much fruitless searching, looking for programmes that actually allow you to greate a galaxy by typing a bunch of numbers and possibly code in, I gave up. But today on Reddit in /r/worldbuilding I found another thread about creating galaxy maps. One comment mentioned a programme called Sketch Up, which comes with a free version. I downloaded it and have spent a little while experimenting with drawing out some systems. I am pretty excited about it so far.
I doubt I will make a universe all in one, but I think creating it as I create the story will be how I go. That being said, tomorrow I might just sit for a few hours and create something amazing.