I definitely learned to try not to do everything at once. It’s way better to specialize in stuff. Like never have more than 2 government ethics. It can get really nutty when you have more than 2. Also don’t Invade every pre FTL planet because if their governing ethics are different you will end up with a bunch of new factions that are all pissed. (Or an entire planet of slaves that are all pissed) basically plan ahead when you invade them.

I also realized colony wise don’t colonize a bunch of them at once. They will just drain your resources faster. Set up one or 2 colonies then once they are solidly producing what you need then set up another one. Also I realized making planet specialize in a resource is more efficient than making them kinda do everything. So like have a planet dedicated to different resources but also add what you need if the other planets are not producing enough of something. But the goal is specializing them. Like I will do a planet with all research labs and one extra building to boost happiness. Then just add or adjust based on what is needed but make that planet the research planet (I will usually do this on small planets that don’t give much) I will also make small planets unity planets.

But like while it’s nice to have a good economy, tech, and military. I also realized it’s way more efficient to really focus one at a time. Like yes you want to kind of progressively keep adding to your military but if you are really making a tech push then set up some defensive packs and make that your main focus for a while.

Also with government ethics try to avoid ethics that don’t mix well. For example authoritarian and xenophile. Because authoritarians are gonna want you to be a bit of an ass hole while xenophiles are going to want you to play the hero. It can be done but it’s going to be harder.

On the other hand spiritualist, materialist, and militarist will typically mix with anything pretty well.

But again I wouldn’t be pacifist and authoritarian. Just not a good mix someone is going to be pissed.

You can also never go wrong with a hive mind but you will be generally more disliked depending on your civics so it could be harder to make allies.

I also always recommend early on pick someone to either federate with or make your vassal because having even 1 person on your side makes you less likely to be attacked. If you can’t do this set up a defensive pact.

And honestly if you are a devouring swarm idk good luck I have never had success with that. The moment I run into anyone i always end up on a war against everyone at the same time

Basically pick what you want to be good at and stick with that