I start a campaign in collaboration mode. What do you want to see in a game? are there things you can live without? then I worldbuild
last game didn't have high elves, no orcs appeared in the 2 years it ran.
the main races were human, halfling, dragonborn&kobold and dwarf.
but when a player wanted to play a warforged, tiefling, assimar, or telepathic-hivemind-conjoined rat-king - "as far as you know you are the only one of your kind, how did you get here/this way?"
the rats were mostly the party mascot as my 9 yr old spawn was unreliable as a player. (much of the time it was just me imitating them) Any one of the other characters would have died for them, but would not trust them with the flying boat.
I don't like the lucky feat, faeries or Aarcokka, for balance reasons. no one has asked about them. Players don't get to pick magic items, the ones they make themselves are done as a collaboration. so if there is stuff that doesn't fit, it doesn't show up. Mostly Items are about power level - I guess a staff of the archmage is okay, if your L17. at levels 1-13 its not going to be around.
We are working on the world for a Bronze age campaign, cut off from ocean trade, one of the players wants to be a classic pirate. "How about a shipwrecked cast away from another civilization? you have the built-in goal of getting enough money and reputation to build your own ship, then you can set yourself up as the merchant king! Right now you are level 2 and no one believes your story of huge ships, that don't use oars." now we are both excited about it.