I've just had another thought about sandwich effects, and how to 'finish' or 'start' them, to make sense...
Paul Harris has a fantastic illusion called 'air of mystery', in which an entire deck of cards vanishes from between the two jokers, and re-appears inside the box.
I am wondering if this effect could be the prelude to an ambitious card routine... here's the description from his book:
Paul Harris wrote:You comment that, Just like the heads of Las Vegas women, a pack of cards consists of ninety percent air. The entire deck is still seen in your hands as you squash your hands around it. The deck, still visible as the hands squash together, instantly disappear . . . leaving behind only an air of mystery. There is no palming, lapping, or pitting. The raw nerve impact of the vanish transcends sleight-of-hand and borders on the seriously weird.
But, with a little adaption, the effect plays as I described.
It's a bold introduction to the sandwich effects, and truly would get the spectator's interest. Plus, the entire deck which re-appears in the box is ungimmicked, so you could go straight into something else!