Husband and I don't particularly worry about the exchange rate - basically we just take fluctuations as they come. We always travel with financial reserves and more than enough funds to accommodate all those little and not so little extravagances that come our way. Our destinations and style of travel differ enormously - it can range from little towns in Cambodia to riads in Morocco, to a safari or trekking, or to skiing in Canada. Every January we allocate a travel budget to accommodate all plans for that year.
Next month we head for Greece and the slight decline of the $A is not an issue with style of accommodation hire cars etc . Just business as usual.
We use ATMS, debit and credit cards, some backup emergency cash. Funds (through cards) are spread over 2 different banks and 2 different cards. Once in Turkey we had a glitch with one of our cards - even though we had advised our bank of where we were traveling. Nice to have the other bank issued cards to enjoy ourselves while we waited the couple of days for the other card to get itself reset.
We use a travel pouch, worn under your clothes, plus a travel belt ie: ordinary looking belt with a zip on the underside. Amazing the number of $100 notes it can hold.
And yes we always think in terms of the cost/currency of the country we are traveling in.