If you're planning a camping trip abroad next year, do not leave changing money until you arrive at the ferry terminal. Certainly, do not use the “handy” ATMs in the UK that offer euros as the combination of poor exchange rate, handling charge and commission is punitive. As most banks appear to resent you accessing your own money when abroad, consider changing to a bank that makes no extra charges for what so many regard as a privilege.
A little forward planning and shopping should mean that you can avoid buying a 'European Road Safety Kit' on a ferry, usually on sale at a ridiculous price. You could enjoy a Blue Peter evening making your own reflective gilets and share the use of other items such as a warning triangle, light bulbs and so on with friends.
Shop around for a good family deal on travel insurance. Annual cover is often a much better option rather than taking out insurance for each trip. Don't forget to arrange a European Health Insurance Card (EHIC) for everybody - www.nhs.uk.
Breakdown assistance is priceless when you hit a problem abroad. The annual charge could turn out to be an absolute bargain and could salvage a holiday.