One of the fun things about science fiction and fantasy is getting into a mindset totally different from your own. It's challenging, too, because you have to still make the alien (or fantasy) species understandable to humans.
I've been having a a lot of fun with the warrior species in The Old Man in the Void. Only known as "The People, they are not one species but two, caught in a war that led not only to the death of every living being, but also the destruction of both their star systems. Nonetheless, their battles continue on in the automated warships they created. One of those warships drags Dex and his ship, the Santiago, across the Event horizon. Dex and Santiago must master the ship and use it to pull them back to reality before enemy drones, the damage to the ships, or the enemy drones destroy them as well.
Now, as you know, I was inspired to this story from Hemingway's The Old Man in the Sea, and so it's probably no brainer that the species are my literary nods to the marlin and the sharks. So I wanted the People to have a different view of killing and death, something more analogous to the Law of Nature, but I wanted sentient, emotional beings, too. So rather than fighting out or hate, suspicion, greed or any number of human reasons, the People view each other as a brotherhood in competition, conflict being a beautiful thing full of honor and bringing change.
From that, I developed the mythology: Hudon, god of war, woos Elomij, the goddess of beauty and change. In doing so, he manipulates the world, twisting it from her own plan, but convincing her in the end that he's improved it with his bloody motives. In the end, however, they will fight and she will leave him, but not because she repents of what they've done, but because she finds constant war boring. She will form a new people, while Hudon finds a new consort--Lady Death.
Since all the People are long dead, we can only see this in the myths and the machinery left behind, so that's been a fun challenge, too.
Another reason for having an alien mind is to contrast it against the human one. Just as we learn by being exposed to new things, so do our characters--and often, the point is so they can learn about themselves, whether they use that knowledge to make a change or not.
A robot passed him by, silent and uncaring, apparently programmed to ignore anything that didn't pose a direct threat. Intent on its mission, the same mission it had been fulfilling for God-knew how long. Had the People been the same way, moving from conflict to habit to instinct, until neither species stopped to actually notice the changes, the carnage, around it? Had they traveled mindlessly into oblivion with the same inevitability of their spaghettified systems spiraling into the singularity? Had there been no Dukochev zones in their entire history, when they had a moment of stability to stop and wonder why they were so intent on slitting their brother's throat? Did they hate so much?Or did they hate at all? Hudon's words came back to him from when he'd told the God he'd hunted both the People and the Worthy Foe: "Is there a difference?" And the myths of the Elomij, if indeed, they related to their ancient roots in this system, never differentiated between races. They chose to be brothers, yet they chose to place victory in the conflict over everything, even their own survival.Is that what I did? Am I in this mess because I was too stubborn to put my own life and Santiago’s safety ahead of victory over some artifact?The map on his faceplate was signaling a junction ahead he needed to take. Time enough later to examine his conscience. Right now, he needed to survive--and that did mean victory over the drones on their way to destroy this ship and them with it. Victory, or at least a draw that would allow them to escape.