So here are a few things to add into the universe to add some variety in the systems. Yes, josh's systems are beautiful, but they run the risk of becoming just another pretty nebula if that's all there is. So in addition to realistic empty systems with no nebula whatever and just a sea of stars around you, here are some things which can spice things up a bit
Based on Real life
Black holes
Come in varying sizes and various sized accretion disks
More than just graphical, they require black-hole-traversal tech otherwise, you become a lovely glowing stream of heating particles falling into it if you get too close.
Protoplanetary disks
These would have a rather flat or toroidal, dusty disks filled with small asteroids to small planetoids. There wouldn't really be anything above or below the disk except enormous magnetic loops shooting dust clouds above and below. Often said disks would also have a frost line that separates the more rocky & metallic asteroids from the more icy ones. also, need not be colored like real life
Carbon (and other) Spirals
Binary systems should definitely be in, but there should also be things like
this carbon spiral. and since this is LT we aren't limited to greyish blue, but perhaps any or multiple colored spirals. They would just be dust clouds with small asteroids when you got close, they are more for "ooh aah" than gameplay.
Imaginary
Starflowers & Plasma storms
No, this probably doesn't exist in reality, In real life this image is actually bioluminescent plankton...I think. However, I think it would be incredibly cool to have giant bursts of light and plasma appearing is what seem like enormous clouds in space. somewhat like a dusty asteroid zone, just plasma, acting almost like bubbling mud, exploding out and falling back in.
Mysterious rings of light
Imagine a system with an enormous glowing ring, it's not a wormhole, there are no planets or stars at the center, it's just there, glowing, spinning, another interesting phenomenon of the LT universe
Tiny Galaxies
Occasionally, an explorer will come across what appears to be a tiny little galaxy, just hanging out in a star system. it appears to be filled with stars and dust just as though it were huge...but the stars are tiny little points of light, and the "galaxy" is smaller than a planet.
Colorcanes
"Hurricanes" of colored gas and plasma filling a system, large explosions with long tails and great magnetic loops of glowing plasma
Whatever this is
Challenging your assumptions is good for your health, good for your business, and good for your future. Stay skeptical but never undervalue the importance of a new and unfamiliar perspective.
Imagination Fertilizer
Beauty may not save the world, but it's the only thing that can