You've had a browse and there appears to be some members who've really caught your eye. Why not initiate contact and see where it goes?
Send a message - what better way than to just jump straight in and say hello! You can send them a message directly from their profile, or from anywhere you see the envelope ("Send message"). They will receive the notification on their newsfeed and it will also be highlighted in their Messages tab.
Comment on their status- if you like their status, let them know. You can do this on the newsfeed or on their profile. They will receive a notification once you have done so and be able to see it in their messages.
Comment on a photo - like what you see? Everyone loves a compliment! Leave a comment on their album photos. They will see it in their newsfeed and in their inbox.
Comments and messages are only visible to the sender and the recipient.