Lie
Never recognize you lied. Maybe she will forgive you, but will never believe you again.
Business things
Women are quite perspicacious beings. Don't share your business with your girlfriend/wife, otherwise you may remain without.
Family secrets
Don't tell her about the secrets of your family if she is not your wife yet. This is very much delicate. For avoiding this, don't leave her face to face with your family. Always be near.
List of your girls
If your phonebook is full of girl names that you "visit" from time to time. Make sure you hided it.
Porn magazines
The majority of women consider porn magazines vulgar.
Friend secrets
Keep your common friends' secrets further from her. Remember that women like to talk much, and the secret will be spread so fast that you won't even understand anything.
