I sometimes go off on a trip - for pleasure or business - with just hand luggage, but then find I "acquire" ( = wife and kids buy, or cause to be bought) loads of extra stuff. Instead of stumping up for extra baggage charges on the way home, I parcel up either the new gear or the dirty washing and head for the local post office. Stuff usually arrives safely and cheaply within a few days. Top tip: Take a roll of parcel tape in your hand luggage on the way out.