The principle behind this is that you auction off money.

Pull out a $50 or any high-value note, and get your mate to match you. With (say) $100 on the table, say that you’re both going to bid for the money, and, being a gentleman, you bid first (seemingly giving him the advantage) you bid the same value as you put in, so in this case, $50.. in order to with the money your mate will bid $55 or something. You accept defeat. He takes the $100 and you take his $55.

One which works well:

For this you need a glass, and three coins, 2 thick ones and one skinnier one, and a table with a tablecloth. Balance the glass on the two thick coins with the skinny one under the glass. You bet your mates that they can’t get the skinny coin out without touching the glass or the other coins and without props. They try and fail, then you succeed by scratching the tablecloth in front of the glass with your forefinger. The coin underneath should slowly come closer and closer untilit slides underneath the glass. Collect on your bet.

Matchstick:

Bet your friends that they can’t hold a lit match upside down for 40 seconds. They try, they fail and burn their fingers. How to do it: the trick is to move your hand briskly side-to-side, the flame will flick at 45 degree angles and thus you avoid most of the heat, plus the match burns down slower – most people can hold out for 40 seconds like this. Make sure you don’t wave the match out. Collect on your bets.

More to come.