Similar to others I carry as little as possible and only take out as needed since Charles Schwab reimburses all ATM fees foreign and domestic.
The only exception is if my transportation to/from airport is not pre-paid in which case I usually take out cash at the airport to cover the ride even if they *might* accept CC to avoid the hassle (in the US I'll deal with the hassle but in foreign countries where I don't speak the language it isn't worth it to me).
I also carry $50-100 in US cash as an emergency but deposit that back into my checking account when I get back to the US (I've never had to tap it).