Some folks have a little pouch sewn into the back of their holster. I'll be darned if I can put my blaster away much less grab cards out of it. Go HWT and sew a pouch under your pauldron. Maybe ask your Vader to sew a pouch in his robe and pretend to give him a cuddle when you run out of cards. I bet some sort of dispenser in the inside of the top of your thigh would work.
Really tho... Handlers are a godsend... I suggest bringing some sith cheerleaders with you.
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Aloha,
-Eric