So I was in the pub last night, fiddling with my cards as usual, practicing some cuts, when a guy from the table opposite randomly yells over "Hey show us a magic trick!" Everyone on my table kinda looked up at me and raised their eyebrows knowingly, so I grinned and pulled my chair over to the next table and somewhat to their disbelief I started a quick routine ("Oh my god, I was just kidding and it turns out you actually are a magician!").
I start off with an ECC with whatever the top two cards happened to be. Normally I'd set it up like a 2s/Ts or a Qc/Qh or a Ad/Ah depending on how much attention they're paying. I like 2s/Ts because even if they're not really paying attention, they'll spot the change because the card goes from mostly white to full of pips. But for impromptu I'll often just turn the deck over and push the top card over and back with my thumb to glimpse the second card so I can alter my patter. If it's going to be an 8h/9h change or some other similar card, I'll possibly cut the deck to try for a more visual change, but it just gives me that heads up as to whether I need the spectator to really pay attention to the card before I change it. Anyway I digress. (PS: Thanks to Beardy for the advice on ECC, it's much better now)
That went down nicely, as I've said before it's a super-fast way to get the audience hooked and convinced that there's something worth seeing here. It's a versatile technique which can be used as a quick punchy effect like that or as something more intimate.
Then I started a small ambitious card with the ace of spades that I knew was 2nd from top, DL turnover, show, turnover and into middle, then "Now you've just seen the ace go into the middle, so there's no way it could be on top of the deck, right?" They agree, I say something like "watch this", DL again to show an indifferent card, act confused, then wave my hands and turnover the top card to reveal the As.
Normally I'm not too sold on the whole "The magician gets it wrong at first but then recovers" story that a lot of effects use, but I'd been watching Oz Perlman's Born to Perform earlier in the day and it looked pretty good when he did it like that. I think it works on the ambitious card because you first show the card going into the middle. Then you show that the top card is a different card, which strengthens the perception that the ace is really in the middle. Then you do something magic and suddenly not only is the top card not the same card you saw a moment ago, but also it's the card you just saw go into the middle! You're actually performing two effects at once, which makes it stronger.
Then fate stepped in and made my job really easy. One of the guys said "Let me do a trick" so I said "Sure as long as it's not 52 card pickup, else you really will be the one doing it <grin>". He needed to set the deck up so I took the opportunity to sample some more of my golden nectar

Finally he showed me four jacks and gave me a nice spiel about the Jacks protecting the deck, and put one at the bottom, one in the middle, one towards the top and left one on top, then a helicopter came along to attack the deck and all the jacks magically rose to the top to protect the deck. I was suitably impressed

But it left me perfectly set up for a poker player's picnic with Jacks! Hurrah! I gave the deck a riffle-shuffle preserving the top four, split into four packets and you know the rest. They were stunned at the conclusion - even though my riffle had only preserved the top three so the final card wasn't a Jack

Finally I ended with a nice simple keycard pick-a-card effect where I have them choose a card, and then simply spread the deck on the table and ask them to hover their hand over the cards while I scrutinise their face to determine that the card he chose was the 9 of diamonds. (Actually, bizarrely, he managed to choose the ace of spades from my face-down fan! Wish I'd had an opportunistic reveal set up for the As like I do with my blank Qh!)
And that was that! The three people at the table were smiling and engaged, took my picture as well as videoing some of it, and actually spontaneously applauded at one point!
