Here's another approach...

Method #1

-Select 6 playing cards from a standard deck
-Assign a tartan to each card
-Shuffle
-Toss the cards in the air and let them land on the floor
-Discard the cards that land face up
-If all cards land face up, repeat the toss & discard
-Shuffle the remaining cards
-Toss the cards & discard as before
-Repeat until you're left with a single card

Method #2

-Assign a tartan choice to each of 6 playing cards
-Throw them at a wall and let them land on the floor
-The card that lands closest to the wall decides your tartan

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