I resumed the work with core beliefs some weeks ago. At first things did not work very well but after some research I learned several techniques for challenging negative core beliefs and come with a method which have been helping me a lot: the use of flashcards.
First of all I challenge negative core beliefs the same way I challenge any negative thought: 1) Gather evidence that the Negative Core Belief is true, 2) Gather evidence that the Negative Core Belief is false and 3) Come with alternative beliefs that better explain the evidence.
After coming with alternative beliefs that better explain the evidence I write them on a flashcard. I also draw a line on the flashcard where I write the negative and positive core beliefs at the end of the line and then write in between where I stand. I use one flashcard for each core belief for reference and review.
I really wanted to work on challenging negative core beliefs since this is the ultimate work on CBT. I am glad I found this method which have been helping me a lot. The result of this work is that it is rare now for doing a thought record.