Now to decide on a rule-set (old Apoc., new Apoc., or just a really big Unbound game with the 7th Ed. rules).
For the Emperor!
Something that I’ve found really cool and helpful at setting the scene during an rpg, is going on youtube and finding ambience or ASMR tracks on a 1, 2 - or more - hour loop. You’d be surprised what you can find on youtube in this regard! I found an hour and a half of library sounds! ’Rainy night at a tavern’ is a seminal D&D piece. Rain with thunder, the sounds of a city, industrial sounds, forest sounds, jungle sounds…
It really helps immerse your players and make them think they’re really there. I’ve even had mine jump a little when on a death world in Dark Heresy and the jungle sounds had some animal roar on it!
I hope these things are helpful to you as well!