Depends on whether you are intimate with other people. Oneitis is a thing. A dangerous thing.
That said, a person becomes more attractive to you if you do favors for them.
So, guys, if you want to attract the girl, don't do favors FOR her - ask HER to do favors for you. Start small and slowly escalate. Literally ask her to step aside, hold your jacket or bag for 5 seconds, and so on.
There is some semi-subconscious rationalization going on. "I normally don't do this. I don't do this for guys. Oh, I did this, so he must be special. I keep doing things for him, so he is the one."