Getting nervous before an exam is just "part of the game" as it means we care about what we are doing.
However, I would suggest a few pointers:
- On the course side, when you are doing the labs no matter whether they're GE or not, try to make new and "customized" exercises. It can be useful to get more experience on the topic. More experience you have, more is the chance to clear the exam.
- Review the exam objectives and try to find a "mental" link between an objective or topic and the lab exercise. This could help you a lot during the execution of an exam task, especially with tricky questions.
- Know the product documentation and where to find an option or menu or configuration or whatever it is.
- During the exam read carefully the initial configuration information and the task questions. Sometimes there are hidden details inside the question itself.
- Doing the pratice with lab exercises is a good starting point as the exam is hands-on.
- It is also a good practice making the exercises until you feel literally nauseous or even you remember the lab questions by memory. This sometimes can show up errors and typo you can make.
- Since the configuration exam must be persistent and not changed by a reboot, you can maybe try to make all the lab tasks then reboot and then the lab grade command and see if everything looks fine.
I cleared my RHCE almost 4 years ago, maybe the environment has changed with the time goes by. These rules should be still valid, though.
I hope it helps
Best Regards
