1) Learn to love your CRP5 (I know, I know, it's a contradiction in terms).
Learn it inside out and practice until you can use it quickly and accurately. Fear not, you'll probably never ever
ever use it again once you've got your first job.
2) Have faith in your groundschool / brushup instructor.
Large parts of general nav were a mystery to me until the brushup course, when I was lucky enough to have a brilliant ex navigator - who took sadistic pleasure in winding up pilots, but was also
extremely good at getting his subject across. After 2 weeks of him I was literally dreaming general nav questions in my sleep, and the exam itself was a breeze. Thanks Baz!