Posylady,
Hi.
I suppose to begin with I would not announce I was there to do Reiki to someone new. Rather, I might introduce myself as a Reiki pratitioner and offer to talk about it a bit if he\she were interested. I would say that one's approach might also need to be sculpted to the age of the person. Many folks of my generation (or older) were never exposed to 'energy stuff' as we grew up, may have some pretty 'olde fashioned' notions about 'energy work', and may not have done anything as they got older to find out about stuff they have heard mentioned. Younger and newagers might manage better with a less 'delicate', approach.
Cheers,
RC