Rather than trying to get sensory evaluation of off-flavors in at this late date, I'd recommend practice judging. Get together with several people and together fill out score sheets on some homebrews and/or commercial beers. Have each person critique what has been written by the others.
This will hone you in on being descriptive and complete.
Practice writing out answers to some of the sample questions, not just for the mental exercise, but to exercise the hand, too. It's tough writing for three hours straight.