Currency changes

Use an ATM debit card tied to your checking account to withdraw cash, just as you would here in the States. Check how much your bank will charge you in fees, so there are no surprises. Credit union cards like mine have very low fees - always 1% of each transaction, no matter which country. My recommendation is to not withdraw too much (only what you need) because it will be impossible for you to use those currency elsewhere, and selling it back (into dollars) will also cost you dearly. Getting stuck with extra kuna and koruna would not be smart unless you plan on returning.

Pmedleo, are you Australian? Most of us on the forum are American or Canadian, and we tend to answer financial questions like yours from the standpoint of the way our financial institutions work. We are highly suspicious of cash cards on which the holder loads money, then spends it, because US cash cards are notorious for being fee-laden and in many cases do not actually work in Europe at all.

I don't know anything about Australian travel cards, though just within the last few days the subject came up in another thread. I would call the issuer of the card and ask what you will be charged when you employ the card in Chechia or Croatia. If they can't tell you about a flat fee and/or a percentage fee, ask what today's conversion rate is. Then go online and try to find the currency-exchange rate at close of business yesterday. Those bits of information will tell you how much extra you will in Europe every time you use that travel card. I can guarantee you that you will be paying something for using that card, and the cost is pretty likely to be buried in an unattractive conversion rate so the issuer can claim that there is "no fee" to use the card.

Make similar calls to your bank and the issuer(s) of your credit card(s) so you know what extra fees you'll be hit with and what conversion rate will be used if you use your ATM card in an European ATM or your credit card at a restaurant, hotel, etc.

You may find that one of your options is much better or much worse than the others, which will help a lot in making a rational decision. Obviously, ATM usage is a bit tricky for short visits to countries not on the euro, because--as previously noted--you don't want to end up with leftover korunas or kunas. If you overshoot what you need and haven't prepaid your hotels, you can use excess cash to pay part of your hotel bill and charge the balance (or use the travel card if research shows that it's cheaper to use than your credit card).

In the US there are some pretty significant consumer protections when you use a credit card. I don't know what the situation is in Australia (or wherever you're from).