Apparently Diana was was good at this, but actually how do you put someone at their ease when first meeting and make them feel they're the only only person in the room

[MariaWaria]

Any tips for someone who isn't Diana, isn't very good at this but would like to be.

I was thinking about this with all the Diana talk lately.
It's made to sound like she had some sort of super-human talent at interacting with others but I think it's worth bearing in mind that an awful lot of how people felt would have stemmed from how they perceived her.
So a basic, pleasant encounter with, say, the person scanning your shopping in Tesco would be just that: a basic pleasant encounter. The same level of pleasant from someone you perceive as hugely important and would be felt as something far more significant and special.
That's not to imply she wasn't good with people, she clearly was - but so are lots of people, so may you be.
I think being genuinely interested in people covers it really, not sure that can be faked.

Getting on this thread

Exactly, DCI. It's one of the oddest things about being in any way famous (I say this based on having a not particularly close friend from home who is a famous actor, and seeing how people are around him) -- the most banal frozen food aisle interaction is disproportionately important to the other person, who then dines out for years on Mn how Hugh Grant or whoever was a great bloke and posed for photos, or was rude, refused a selfie, and said only 'You're blocking the fish fingers'.'