Do not try to memorize your written declaration word for word! This is not a poem recital. If the IO discovers that your answers are taken exactly from your affidavit, he or she will be very suspicious. You should already know the important facts of your case well enough that you will be able to talk about naturally.
In many ways, an asylum interview is just like a job interview. The person who interviews you is there to determine if you are the right candidate for the position. YOUR OBJECTIVE IS TO SELL YOURSELF AND TO HIGHLIGHT ALL THE IMPORTANT AND RELEVANT FACTS NECESSARY FOR HIM OR HER TO MAKE THE DETERMINATION THAT YOU DO INDEED MEET THE CRITERIA FOR THE POSITION. YOU WILL ONLY BE GRANTED ASYLUM IF YOU HAVE BEEN DETERMINED TO HAVE WELL-FOUNDED FEAR OF PERSECUTION FOR BELONGING TO AT LEAST ONE OF THE ESTABLISHED CATEGORIES. You need to focus on selling the persecutions that you have endured, the fears that resulted from these persecutions and the fears you have of being sent back to the COP. Remember to always make it a point to always provide these crucial facts (persecution or fear of persecution) in your answers even if you are not directly asked about them. The best approach to answer any question is to always answer the question you are being asked first and then point out such crucial facts because they are sort of related to the question being asked.