The one thing I have noticed is currencies required in SE Asia such as the THB or USD (for Cambodia) are often longer and narrower than European currencies, such as the EUR or GBP.
Hence, when I purchased a wallet in Thailand, it wasn't suitable for use back home in the UK. I now have that assigned as a "holiday wallet" for use in SE Asia. When the trip is over, it just gets thrown in the safe and contains a few thousand baht, my Thai SIM card, my Kaskorn ATM card, a SIM tray key and a few other useful items, all ready to go for the next holiday.
Also, before going out for the evening, I sort all the notes so that they are in order of denomination and the 500s and 1000s are separate. That reduces the chances of an error after a few drinks in a poorly lit bar.