I've noticed I'm not very emotional when talking to girls and not only then. I'm very introverted and reserved by nature.

Today I was talking with a girl, and she was the one who initiated conversation. I was cold and distanced, which probably made me too serious. I have a deep voice and that also sometimes makes it difficult to understand what Im saying. I also used wrong body language (my arms were crossed), but I noticed I wasnt relaxed enough to uncross them. I asked her out but she said she doesnt have time. Obviously she lost interest during conversation.

How can I present my traits more attractively, without looking sad or angry, and generally make conversations more natural without being forced?