We can create relationships, familial or not, based on god traits. A god of love and a god of hate can be twins, as can the gods of life and death. The god of winter and demigod of snow can be parent and child. While these are a bit predictable, symmetry is appreciated and easier to remember. Gods can be friends and enemies, too. This often results from conflicts of character and desires, just like with people. If these boil over into arguments that become myths, this helps justify the intensity of bonding or resentment. Not every god in your pantheon needs details worked out, but a few will create the impression of depth we’re after.
Where Do They Live?
Deciding where your gods live will have an impact on stories if your characters ever need to visit them. In theory, it shouldn’t be easy to reach gods; otherwise, every guy with a cause will beg for help. A useful tradition to follow is that one must prove one’s worthiness through an arduous trek to the god.
Do the gods live apart from each other or all together in a city? I recommend avoiding something as obvious as a mountain top because readers will be reminded of Mt. Olympus. On the other hand, the god of the sea living underwater makes too much sense to ignore, but we can still have him do something less common, such as dwell on an island; after all, how is anyone supposed to visit him underwater, or is that what he’s trying to avoid?
Are the gods in the mortal world, like your planet, or in a magical realm similar to an afterlife? What sort of guardians protect the path there? What price must someone pay, literally or figuratively, to get there and back? You can base your decisions on ideas from existing mythologies about travel to other dimensions, such as Charon, but a guy ferrying people across a dangerous river for a price is another idea that’s too well-known to use without inducing eye rolling.
If the gods are believed to live in the sky, what happens in a world technologically advanced enough to explore the heavens and discover there are no gods up there? They would likely alter their beliefs to compensate for this. But it could be interesting if the gods are real and are indeed up there. Maybe this is the reason advanced technology was sought. There could be important questions the gods must be asked.
Where did your gods come from? “Nowhere” is a valid, if not entirely interesting, answer. On Earth, we don’t talk much about where God came from so much as where we did. We can avoid this question altogether and few will question it. We don’t actually need a reason, but something is usually better than nothing unless the idea doesn’t hold up. We may never have a chance to mention it in stories anyway.
Our gods could’ve come from another world that they’ve abandoned or destroyed. Is your new planet their second or third chance to get it right? Maybe the gods are fleeing enemies, or they are the terror of the cosmos that other pantheons flee. Did they leave a planet full of life behind? That planet could be the one you’re setting up now. If the gods abandoned a world, decide what’s happening there now. Is that where Earth’s God went? Is He too busy setting up other worlds to drop in?
Consider what the origins of your gods say or imply about them. In Greek mythology, the gods came from the giants before them, but if gods can be born, they can presumably be killed, too. If your gods can die, what happens when one does? Maybe the one who killed them can replace them. A magic or technological weapon might be needed to do it. Perhaps only other gods have the power to destroy one. Maybe they can only become injured. Or imprisoned—and what happens when this occurs? What kind of prison can hold a god? Decide where it is located, how is it guarded and by what. Does their influence over the world stop as long as they’re locked up?