You may not be 100% confident in every area of your life. Who is? Play to your strengths. We have all seen the dude with women that seemed to be out of his league. How did that dude get that chick??? He played to his strength.
Looks, charm, physique, conversation, humor, intelligence, dance skills.
Any one of these can open the door to interactions with women. Be confident in the realm in which you excel, use that to make yourself comfortable talking to anyone. Why? Because you rock the conversation or the dance floor or the humor or the looks or the battle of wits.
Once the door is open, recognize attraction and act on it.