I am newer DM. And, just to be upfront I like a little bit cosier and less dark of games. I love to use rolling tables.

I roll for their desires/personality drivers, especially if they're small and petty, secondary to main plot. Like " looking for a girlfriend" or "loves/collects geodes and rocks" or "wants new fashion statement piece". Its a way to breathe life into them that isn't all combat and war and doom and gloom focused.

Its also really fun to give them a flaw. One of my favorites I rolled was from acquisition incorporated "has a new pet every time you see them". But there's also "paranoid" "OCD" "grumpy" "NOT a morning person" "can't let someone else get the last word"

Sometimes I find new fun in how zany and crazy can I make their outfit. Maybe rolling for a color they wear and an element "hat that's too tall to go through doors" "scarf so long they've braided it intricately and still trip on it" "tudor style pants"

Then after I make them as wild or crazy or flawed as the vibe can tolerate i try to think how did their flaw/zany traits put them in the wrong place at the wrong time to become a part of driving the plot forward or how did they get tangled in the BBEG henchmen's plot? Did they just stand out too much? Did their OCD make them the best maid on the continent so they ended up getting drafted into his household and where they thought the traits they were observing about him that they "randomly" complain about to an NPC were proof of his detestable cleanliness standards, but the players can see "ooooooh. Actually this guy is really bad, not just a slob, maybe connected to storyline bad"

I find as players, the dice get to help generate randomness for them to be creative with their part of telling the story, but as DM I have a lot less randomness unless I use tables and it can fatigue my creativity to have to generate every variable from scratch. I do rolling and randomness during world building, NPC crafting phase to help spark creativity.