Having done psychometry in the past, I have usually used an item, either belonging to the person I am reading for or an item belonging to the deceased.
However it can also be done from a photograph.
Sometimes, a photograph can be worth a million words. I am sometimes amazed at the information that comes through, more so the person, usually a stranger, is even more amazed.
One friend in NZ gave me a photograph of her parents. I never met them, they had died years before.
We had all been drinking wine, it was Xmas 1999.
I quite shook her up when I told her that her mum had almost married someone else and had broke off her engagement just the week before she married her dad!
Sometimes....wine and psychometry do not mix!