a few tips from me (senior crew BA)
Just my 3 pence's worth. I have been flying as crew for 14 years (kind of average) - nothing of note happened. Check/google the stats - flying is very safe compared to crossing the road/riding a motorbike etc. Enjoy the experience. Get a seat near the wings, away from the window. Browse in the terminal. Enjoy the space, the architecture, admire us the crew gliding across and parting the crowds, get on, listen to the emergency demonstration, enjoy the meal, say thank you to the crew, do the inflight entertainment, have moderate amount of alcohol, have a sleep and get off. There is nothing to it. Bon Voyage.