Just like airfare, meals and taxis, tips for good service should be part of your vacation budget.
To avoid over-tipping or not tipping at all, personal finance web site, kiplinger.com, advises having small bills on hand.
It is a good idea to keep a nice, fat wallet with all those singles and fives. You might want to pack in some envelopes so you have something to put the money in for the housekeeper.
Housekeeping staff typically get $2 to $5 each day.
Airport skycaps and hotel bellhops usually get $1 to $2 per bag.
Valet parkers typically get $2 to $5 each time you pick up your car.
Airport shuttle drivers get $1 to $2 and extra for baggage handling.
At some hotels and resorts, tips may be included, so read the fine print. At the bottom it will say "gratuity included" or "service is included" and it will usually be around 18 percent. So if it has been extraordinary service and you would like to tip on top of that, do so, but do keep in mind that it is already included so you don't end up accidentally over-tipping.
Brush up on tipping protocol before you go overseas. In some cultures, it's an insult. In others, it's already factored in to your bill.