Having just returned home from two weeks motorhoming in France, I was surprised by how expensive everything is over there. The Autoroutes are great with considerably less traffic than our motorways but the cost at the toll booths soon adds up.
Given high costs of travelling in Europe it is ever more important to get decent rates when changing Sterling into Euros. In the past I used to use the Post Office which offers much better exchange rates than the airport or station Bureau De Change. I still find this useful for small amounts of cash but for larger amounts I have been using a pre-paid credit card from Fair FX. The rates are usually even better than the Post Office and I find it very easy to use and very convenient. You can load the card with a specified sum online and being a Mastercard, it is accepted at most outlets. If you need cash you can make cash withdrawals at most cash machines and I feel carrying the card in my wallet is safer than carrying large amounts of Euros and more convenient than Travellers Cheques.
I do not intend this as a recommendation, simply sharing a positive experience. There are quite a number of such pre-paid currency cards and if you wish to investigate these, this link will take you to some research from Which; http://www.which.co.uk/money/credit-cards-and-loans/guides/prepaid-cards/euro-and-dollar-prepaid-cards-reviewed/