I'm a clairsentient. I'm not a fucking cheat, and I don't make any kerching from this small ability.
I ahve had messages for myself from family members, and for 3 other people. So I am no Derek Acorah 
I get: overshadowing - this is where the deceased 'tell' you how they passed over by recreating the feelings in your body. So if you get pains in your chest and a tingly left arm, it's a fair bet that is referring to a heart attack.
I, for instances, got the symptoms of a stroke down my right side, (complete with drooping face, thanks for that!) and a warm glow in my heart, emotionally speaking. I knew it was to do with a lady sat to my right. Not her mother, older than that, grandmother? I got the word 'support,' by that I mean I saw the word, in bold type, in my mind. I had a chat with the lady and she seemed to feel I was correct. Me? Buggered if I know, it felt very authentic and very physical to me, which I wasn't expecting.
A few points:
- I think that there are some famous mediums who are chock full of shite, imo.
- There are some bloody good ones too, I do know a few personally star fucker that I am
- Derren Brown made some bloody good points. Some 'career' mediums do cold read, some deluded mediums geniunely have their head up their arse and believe that they have the gift and are ego driven to helping people, in a saintly fashion
- What Derren Brown proved, to me, was that the medium he was studying was, most likely, not genuine. He did not disprove the theory of life after death, or debunk every medium in the world. Nor would he claim to, I think.
I am sceptical about everything, but on this I have to say... despite seeing spirits from a young age, despite it being in my family to have 'the sight,' until relatively recently I have been
at mediumship - until it started happening to me. And yes I have had my eyes, and indeed my sanity, tested by doctors and I'm fine, thanks.
I don't expect people to 'believe' if they have not had personal experience, that, for them, confirms it.
But I promise that I am not a liar, and I really resent being called one so don't go there! I'm not a cheat, apparently not insane, not deluded, and I'm not stupid enough to confuse dreams or my imagination with reality.
If you asked me if there is 'life' after death I would say yes - I think so.
People are often very desparate to say that it has been disproved already, as it is, let's face it, a very disturbing concept. Which is why few mediums will come and defend themselves, they know they won't change anybodys' mind.