This is an interesting subject, and I think that KD above is definitely on the right track about the practicing. Using a persons first name when speaking with them, keeping conversations light, and smiling will make others feel at ease...which in turn will make you feel more at ease. Many sales people wear name tags...Practice saying hi Jennifer, thank you Jennifer....or have a nice Day Jennifer...be sure to notice how their faces light up when you use their name. It's not everything...but its a good place to start.