I'm travelling around Europe and want to convert some money to Euros. What's the most cost-effective way of doing this? Should I convert as much as I think I'm going to need in one go, or withdraw from ATMs as I go? Are there any banks which are better than others on exchange rates?
First up, you might want to start by looking at this question, which has some good general tips.
As you're in the UK, and starting with pounds, we can be a bit more specific. First up, you probably don't want to be using a UK debit card, as almost all of them have very high fees (think a couple of quid plus several %) per withdrawl. Several cards that used to be free (eg Nationwide) now charge, so beware! Secondly, changing cash before you go, or when you're there, is unlikely to get you a great deal - the "spread" (difference between buying and selling rates) is almost always quite large and eats into the rate, and that's before commission.
With all that in mind, the general advice is to get a card with low/no foreign exchange and cash withdrawl fees, and use that. Use this to take out cash as and when you need it (and if it's no fee, there's no need to change loads in one go, take lots out etc).
The current advice (June 2011, but it's been unchanged for about a year) is to get a Halifax Clarity card, and be pro-active on paying it off. (They apparently object if you leave it in credit...). The card has no overseas fees and no cash withdrawl fees (but interest does start accruing), so you can use it to take cash out as and when you want it.