My 2c. I traveled abroad recently and here are my tips.
Dereko is correct above. Revolut charge 2% on ATM withdrawals over €200 per month. Check with your own bank. They may charge a percentage also on top of their exchange rate. So Revolut might still be cheaper.
As my holiday went through the end of a month I withdrew €200 equivalent before the end of the month and €200 at the start of the next to get €400 fee free.
Revolut has a great feature in that you can disable the card from the app. My card is permanently disabled and I only enable when I want to do a transaction. This did catch me out once though when I was at an ATM with the disabled card and no internet access. But a two minute walk to a better signal sorted me out.
If you have a Skype account put a couple of quid on it now. So when you are abroad and if your card gets blocked then you can use Skype to call your bank (bring the contact numbers for all of the credit / debit cards that you have). I had to do that in an airport in Asia. The call took 10 minutes but it was on Skype so cost me about 20c.
I never bring foreign currency with me when travelling. There is always an ATM close to the arrival gates and I've never been stuck.
And install your phone app of choice on your phone (Line, WhatsApp, Viber, Skype, Signal, whatever). If you need to call home or text home use that. Free all the way as long as you get a local SIM or connect to hotel WiFi and the receiving party uses the same app.