The turkey has been devoured; the leftovers are cooling in the fridge. Now, it’s time to shop! The Retailers Association of Massachusetts predicts sales will be up 3.5 percent over the holiday period compared to last year. That prediction, based on a survey of the group’s 3,500 members, is slightly below the national forecast of 3.9 percent growth in holiday sales. What are your strategies for surviving Black Friday? Is the chaos worth it for the savings? How do you find the best deals?