one thing that might seem a little contrarian.
let a chick bend over backwards for you from time to time. don't do everything for her all the time, make her put in work from time to time even if you could easily do the task yourself.
i got this one chick she would often call me when she'd be in a jam or needed a favor. and i committed many simp sins in that time. see what people need to realize is that tricking doesn't only mean money. you can also trick time and work on them. if you act out of character in order to please a woman, odds are there is either some simping and/or tricking in there somewhere.
anyway, it took me a while to realize that once i started to ask chicks to cook/bring me food, run errands for me, etc,instead of me doing shyt for them, they actually started to feel me more and catch feelings. i think the reason is that by doing that, you're changing the framing of the relationship. suddenly she's the one trying to get in your good graces and wanting to impress you. she's putting in work and sees it like an investment. it makes her vulnerable because if you drop her after she just did all that for you, now she's looking like a sucker/female simp. so naturally she will want to be more than just friends.
now i'm not saying to let it be a one-way street. but like someone else in the thread said (i can't remember who and the thread is too long for me to search through but who ever said it, props to you), whatever you do, let her do 2-3 times more.
it's kinda like how people used to make sacrifices and offerings to the gods. funny enough, they love the gods even more. had the gods refused all offerings, the people would have probably grown to resent them. so don't be that dude who always refuses for his love interest to do anything for him on some "your my queen, i don't want you to lift a finger" type shyt. she will resent you. play it right with the right balances and she will adore you like a god.