I can't speak for all women but I'd say my top three are:
1. choosing the wrong person
2. having unrealistic expectations of them
3. ignoring the red flags

1. They forget about themselves

Primarily related to hetero couples but can work elsewhere...your mileage may vary.

Thinking they will "change" him....no you wont.

Forgetting that men need to do things. Getting pissed because he offers solutions when you just wanted to vent can be avoided by understanding that men think they are being loving and supportive by trying to make things better. (Men can work on the opposite of this too, that sometimes listening is best).

Not meaning what they say. From white lies or omissions designed to not hurt feelings always bites you in the end. Guys dont do hints well. We try but tend to be blunt. Being direct can hurt but missunderstanding intent can hurt much more.

I think a lot tend to have unrealistic expectations of how relationships work. They try to form something out of nothing a lot of the time and it just ends up being a mess.

1) Changing themselves to fit anyone else. If they dont like you for "you", then what's the point? Plus, you're going to he considered "boring".

2) Not having their own opinions. If you agree with everything automatically, then you have no respect for yourself

3) Not telling your mate what you want. No one is a mind reader, sometimes hints dont work.

Thinking it’s their way or nothing.
Thinking if they’re not sleeping with you that you won’t sleep with someone else.
Thinking....

Not communicating what needs to be said when they're upset.

Comparing theirself to other girls.

Being too dependent.

Not admitting when the man is right is the only one that matters.

Get in them

Complain incessantly about them

Stay in them longer than they ahould