Okay so I've been thinking about this a lot, so here is how I imagine Lily Evans/Potter:
Lily who always leaves the house with open hair but ends up putting it in a messy bun after approximately 3 minutes.
Lily who paints her nails the same color as her hair.
Lily who's nail polish is always chipped because she picks it everytime she's nervous or bored.
Lily: "Yes James, I know that our house is full of plants, but just look at this tiny precious thing, we have to adopt it, it'll suffer here if we don't rescue it."
James: "Lily for heavens sake we're in a garden center, not an orphanage."
Lily who braids Sirius hair.
Lily who's favorite color is green.
Lily who loves wearing bright colors that clash with her hair color and somehow it always looks good and fashionable on her.
Lily who has a huge closet overflowing of bright or patterned cloths but only has 2 plain shirts.
Lily who only has 3 pair of shoes: one pair of running sneakers, her favorite sandals for every day and a pair of heels for special occasions.
Lily who's favorite flowers are Petunias and she has them all over her garden.
Lily who's extremely protective over her plants.
James:"Remus, Sirius, who stepped on Lily's Tulips?"
Sirius:"How would we be able to do that James? They are in a pot on the window board."
James:"Not these Sirius, the ones in the garden"
Sirius:"Oh yeah that might have been me"
Remus:"Lily's gonna be hella mad" James:"May god protect you Sirius"
Lily the biggest Lgbtqia+ Ally there is.
Lily who doesn't dress fancy often but when she does prepare to get your breath taken away.
Lily who usually never wears makeup but she's damn good at it.
Lily who calls James Evans sometimes.
Lily:"Oi Evans, wanna go on a date with me?"
James:"Lily we're married and have a child and also you took my name!"
Lily who gossips with Remus about everything. Literally everything.
Lily who protects Sirius with everything she has and if anyone dares to insult him she's ready to kick ass.
Lily who comes up with ridiculous nicknames for the Marauders because "if you can come up with nicknames for yourself I can call you what I want fly swat".