In a pinch, you have a perfectly good embossing buddy that works wonderfully! I store mine in my empty embossing powder bowl. I also rub it around that same bowl before I tap any excess embossing powder in it - the powder pours back into its container without sticking to the bowl!
Tapping it lightly on the paper, the cornstarch keeps all the embossing powder off your card surface except exactly where you want it.
Thanks for reading!