The lights are on
I thought it best to make a guide and try to help people obtain the 2 Caravan achievements/trophies in New Vegas. In order to obtain "Caravan Master" you have to win 30 games of Caravan (Note: Caravan is not fun IMO and I doubt you will enjoy it, do yourself a favor and only play it for the achievements/trophies).
Anyways, My strategy for Caravan is to load my deck (of which should be exactly 30 cards) full of 5s, 6s, 7s, and 8s. If you run out of those use Jokers until you hit 30. If you didn't know the objective is to make all three stacks (or "Caravans") reach between 21 and 26. Well, 5+6+7+8=26. You have to put the cards in either ascending or descending order. When you get all "Caravans" close to 26 you should win. I say should because I'm not entirely sure what the win system is in New Vegas.
Now, that is my strategy. If you believe you have a better one, feel free to message me and I will update the guide. If you have any trouble message me and I might be able to help you. Anyways, good luck and happy hunting.