Regarding the last tip about using sterling on the plane. It is not always the best option as on my recent flight to Sicily from Luton with Ryan Air, the buffet cart and menu is all priced in Euros, if you wanted to pay in Sterling you paid the same numeric value but in pounds so if something cost 5 Euros it would be £5. It isn’t a great deal of difference with the current exchange rate but it certainly wasn’t cheaper.