I was just thinking... it would be kind of cool if you did Distortion, then said "know how I do that?" and when the spectator says "how?" you say "carry spares!" and reach in your pocket to pull out a handful of cut-out diamond pips.
That would be a good comedic interlude between changing the four to the six, and revealing the actual four. It's also a great opportunity to get your hand in and out of your pocket for setting up the next trick.
I'm never going to do Distortion, so anyone who wants to use that can feel free to do so.