I am feeling pretty good about the twelve species that are traveling through space. I got a good idea of their overall feel, their general culture, and how they play into interstellar affairs. Which actually really surprises me. Out of unlimited options, I put together a practical selection very quickly without thinking much about it.
In Stars Without Number, the Tech Levels are pretty broad, with societies that have digital technology being TL3, and those that have hyperspace drives and artificial gravity TL4. I might perhaps one day add individual planets that don't have widespread electronics yet, but even their wealthy elites with access to alien technology should not be relevant players outside their homeworld. On the other end, TL5 is lots of stuff that is way more advanced than I want to have in the setting. Things that we now can imagine as being plausible one day, but which just don't appear in 60s or 70s sci-fi, so I think they would not fit the overall tone.
This means the twelve species are all TL4 or TL3. And while I first had the plan to make it mostly TL4 with a few TL3s, trying to pick which ones are which makes me want to set a full half of them at the lower TL3.
So curently it looks like this:
TL4: Reds, Giants, Mantises, Aquatics, Caterpillars, Whites
TL3: Drones, Porpoises, Lions, Reptiles, Hippos, Amphibians
This would be the overall tech level for the domestic industry of their homeworlds. There can be some shops on TL3 worlds, particularly in the major spaceports, that sell imported TL4 items.
There might also be
foreignalien companies, that have established local factories that produce certain TL4 items with trained native workers. (Which can make the local producers without the technical knowhow and investment capital quite bitter, because of setting themes.)
With the help of imported space ships, these TL3 worlds are capable to set up their own planetary and even orbital shipyards to build smaller ships like corvettes and frigates, but they still need to buy hyperdrive engines from TL4 companies to install in those ships. Some might also buy gravity systems, while others just go without them. The systems build from domestic parts are of course lower quality than those from full TL4 shipyards.
What this means is that most species did not develop hyperdrive technology themselves, but gained access to it from other species that visited the system. Half of them did obviously, and it seems likely that several of the TL4 species started the same way.
It's something I don't recall having ever seen explocitly anywhere, but when you think about it, it's clearly implied in Star Wars. Particularly in the EU, where many homeworlds are portrayed as places that clearly have very little industrial capacities of their own. Though the Galactic Republic is a single federal republic, so free transfer of goods between the systems is simple. What I want to go with is more along the lines of having a few TL4 worlds that export weapons to other states like the US, Russia, Germany, and Britain. So you could have battles in which Lions fight against Reptiles, both using the same Mantis ships to shoot at each other. Or two fleets of Hippos facing off against each other, one using their domestically build ships with Caterpillar engines and the other using Giant ships.
There's probably a good deal of further details that would be implied by such a context, particularly in regards to national identity. You could totally have proxy-civil-wars like Korea, Vietnam, and Yemen, where one species does almost all the fighting, but they get their weapons from different suppliers.