Look it's dead easy! Nothing painful or difficult. you just lie there and think about your flowers or football or whatever is yourt thing, and let them get on with it. They will be friendly and welcoming and chatty. All they want to do is tick boxes. Nothing to be uptight about at all. They are not looking to fail you, and just want to be assured you are up to the required medical standard- they want you to get through. So treat it as a chance to natter with the Doctor and catch up on aviation/medical gossip. I've been doing this for 40 years and actually enjoy the experience. You build up a long term relationship with your particular favourite Doctor. I can't say enough relax and take it easy, and you will find over time it's actually a not unenjoyable experience.
Now sim checks..........