I could be extreme and say that a man should never be friends with a woman, but that would be over-simplistic. There are absolutely times when women can be good friends, even if initially you were interested in them for other reasons. What I would say though is that you should only be friends with a woman if you really want to be, not as a strategy to try to get laid. If you approach a girl because you’re attracted to her you shouldn’t become her friend and then later try to get with her, you should try to get with her first and if she’s not interested then it’s up to you to decide whether or not you actually want to be her friend. I’d recommend NOT becoming friends with women that you are very strongly attracted to.
Being “friends” with a girl that you secretly want to bang is not a good strategy at all. By doing that you’re creating an emotional attachment to a woman that you don’t even know is attracted to you. When you find out that she’s not, you will suffer a great disappointment and a lot of frustration and it will be a lot harder to forget about her than it would have been if you had made a move right at the beginning. You’ll also end up meeting her boyfriends and all of the guys she’s dating. She might even decide to start hooking up with one of your friends. Plus, of course, you’ll end up wasting a lot of time and energy on someone that doesn’t like you back.