First and foremost is "Can my opponent make a Gami on the next move." If the answer is "Yes" the obvious card to take is one that breaks up the opponents Game. If the answer is "No" then next is there a card that will help you make a Gami on the your next move. If the answer is "Yes" then take it. If the answer is "No" I find the best card to take is the last card your opponent put in his/her hand from the stock. Your opponent has a plan and that card helps to achieve that plan.