Yes, for most of Europe, Euro sure makes it easier.
We have a debit card we tank up with balances in different currencies, on top of Euro, like Scandinavian currencies.
Don't want to shift between different currency balances unnecessarily, due to fees.
We weren't planning on gathering any currencies for the eastern countries, like Romania, Bulgaria, etc.
QUESTION: when travelling in these countries, what payment instruments are easiest or cheapest to use?
Cash (from currency exchanging), Visa credit, Visa debit cash out of ATM.
Maybe some of these countries still accept $US or Euro or Pound and give a good rate.
Interesting to hear different strategies, given Access, Rates, ability to change back any bank notes exchanged etc.

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Epic European 3 mth motorcycle tour http://www.ozemate.com/eu
"Posterus Initium Hodie"

Hi,
I prefer using cash. One reason is when I come home from the trip I don´t want to get a bill later, to pay all the expences after the trip.
Another reason is that in my country, the exchange rate of Visa card is more expensive than the rate of cash money. So when using a credit card abroad everything would be a little bit more expensive. Also when drawing money from a ATM using credit card, I have to pay a fee.
Euro´s are widely accepted in non-Euro countries in Eastern Europe but I prefer to use local currency as much as possible.

Credit cards are widely accepted. You can withdraw local currency from ATMs. Banks or forex shops will change USD or EUR.

Get a Wise account and their debit card - you can even get one that only lives on your phone, if you don't think they will ship one quickly enough for your trip.

Keep the balance in your home currency, and pay in the local currency, get the midmarket rate, which is just about the best you can get with a card. Everywhere in Europe will accept it - in fact the country where you would have the most trouble with anything other than cash is not Eastern Europe, but (less so now but still) Germany!

In terms of cash: if you do want to use it, bring your own cash and exchange it at your destination. You're from Australia? The rate to buy Euros in Brisbane is going to be worse for you than the rate to sell AUD in Europe, just because there is an inherent cost to getting the remote currency to the local exchange point. You just withdrawing it from your airport ATM and delivering it to a European exchange shop is doing their work for them, and you will be (slightly) rewarded.

Obvious caveats apply: avoid airport exchange offices with terrible rates, and avoid Euronet "universal" cash machines like the plague. Withdraw or exchange cash at a local bank office/machine. Wise debit cards don't charge you for withdrawals (up to a reasonable limit) on their own end, but the local bank might still add a charge - I paid something like 3-4 euros per withdrawal in Croatia, and that's within the eurozone!

Where euros are accepted in non-eurozone countries, the rate will of course be worse than the official one (you'd have to go to Cuba or Argentina or Venezuela for a better-than-official rate on hard currency), but it's frequently in places so cheap for an Australian that you won't care. The best example is probably Bosnia and Herzegovina, where the official rate is 1.96 Bosnian marks to the euro, every tourist-facing shop accepts euros at 2:1, and the difference is not worth the headache.

I found cash and ATM withdrawals to work best overall. Most places accept cards too, but it's handy having some local currency on hand.

I agree with the others that Wise is super convenient for getting money abroad - their rates are usually really good. That was my main source of funds. Just be aware you may have to pay a small fee per ATM withdrawal.