This would probably be my own personal plan for the whole exam. First 10 min of reading time, look over the extended response section and in your mind, decided on the Q's that look easy to you and you may do first and the ones you may leave till later on. Then in the last 5 min of reading time, quickly skim over the multiple choice. Once writing time begins, I'd spend 30-35min on the MCQ as Watchman said, just to get it out of the way while its fresh in your mind from reading time. After you've completed that section, do the questions in the extended response that looked easy to you in the reading time and leave the harder Q's till later. If you're spending too much time figuring out a Q, just move on the next easiest question. That way, you save yourself suffering from any panic attacks or anxiety.