We are traveling to countries where I will need the euro and pound as currency. I have read online that I should just go to a bank in that country and get what I need from an ATM. I have been to Ireland before and have successfully navigated money transactions. The trick for me now is spending only 2 days in Dublin, 2 in Belfast, and the rest in Scotland. All of my hotels, transportation (except a few taxis), and lodging have been pre-paid. My strategy thus far is to create an estimation of expenses to help me know how much money I may need. I have read older posts that say don't get the Scottish notes, just pounds. I also have been told that some places will readily take the American dollar. Suggestions are appreciate.
If you need cash in Dublin go to an ATM to get Euros. Otherwise use debit/credit cards to buy things just as you do in the US. Do the same in the UK for Sterling.
If you go to an ATM in Scotland or Northern Ireland you'll likely get Scottish or Northern Irish pound notes. Try not to take these back to the US as you may find it difficult to exchange them at a US bank. If you do end up with lots of Northern Irish or Scottish pounds exchange them for Bank of England notes before you leave.
I also have been told that some places will readily take the American dollar.
Only at very poor rates. The US dollar will be as useful as the £ is in the US.
If you estimate on the low side and then find that you need more cash, it's pretty safe to assume that you will find another cash machine.