Some observations based on Starfinder experience.
1 - You want to start above or race past level 1.
2 - Work hard during chargen, worldgen, and opening posts to establish a solid and consistent tone. Post a stake in your mystical-to-scifi and gritty-to-epic coordinates so the characters can feel like they're all from the same game, take some time to plant your feet, then shift as necessary.
3 - Figure out how you're going to handle crime and be transparent about it. Salvage law, murder in self-defense, first degree murder of evil space necromancers, and breaking and entering are going to be things you want to think about if you're assuming a relatively modern society recognizable to modern human beings, but is not really addressed in the D&D-esque framework of Starfinder.
