I haven’t done a lot of pillion riding myself but my wife has on the back of my bike. I would suggest some things to think about.

Firstly is kit. You will be far more comfortable if your kit is right, once you are comfortable then you will be less anxious. I suggest you go for textile kit as you will be changing height a lot and temperature. Get some gear that you can get stuff underneath for warmth but also fits well if baggy. Reminder you can wear stuff over your kit (waterproofs fleeces etc.) Get a strong pair of boots. I like enduro high boots but others recommend lower ones try and see which you prefer.

Train: The Next thing is fitness and strength. If you on the back of a bike for long periods it pays to be fit and have some strength to help load it pick it up when it falls over, and hang on when it gets rough. If you are fit you will tire less and long days will become less stressful.

Read : Read up about the route and the bike you are sharing. Read the maint manual, and the user book. It helps to understand the problems without having to ask dumb questions when every one in stressed. 3 times during breakdowns on our last trip my wife solved the problem before i had stopped my initial bout of swearing and despair.

Languages : If you are off to places that have a different language go to the library and get a language course. Learn before you go and take it with you if you can. You have lots of time on the back to learn and listen to music. It really helps when you get lost or need to sort out a hotel if the pillion can jump off and ask directions or sort the room out as they are better at the language.

Some Ideas

When it gets scary its far easier if you are prepared.

BD