Are you a little uncertain when it comes to tipping?  Not sure who and how much?  Here’s a quick refresher that will prepare you for your next trip. 

The first rule of tipping is to have plenty of $1 bills on hand.  Literally, in hand.  Avoid the frantic fishing around in your purse to get a tip out.  Keeping it handy will also prevent you from discovering at the last minute that you only have $20 bills.  Try getting out of that situation gracefully.
 
Taking a shuttle to the airport?  A $2 tip per person is appropriate.  Checking your bags at the curb?  Tip at least $1 per bag.  You can take a breather on the airplane - no need to tip the flight attendants, even when they serve you alcohol.  When you check into a hotel, the normal tip for a bellhop delivering bags to your room is $1 to $2 per bag - maybe more if he’s really cute.  The hotel concierge is a great source of local knowledge and can guide you to the best restaurants and points of interest.  If the concierge provides good service, a $2 to $10 tip is customary.  It depends on whether he’s just reserved you a good table or scored good tickets to the theater.  Is your car valet parked?  Normally a valet is tipped $1 to $2 each time he delivers your car to you. Catching a taxi instead?  When the doorman hails a cab for you, tip him $1 or $2.  Taxi drivers are usually tipped 10-15%.  Before you check-out from the hotel, if you’re happy with how your room was cleaned and stocked during your stay, leave Housekeeping $1 to $2 for each day and leave the tip in the room, preferably in an envelope. 

For restaurants, 15-20% is the general rule if service was good. Be sure to look at your bill before tipping and verify that a service charge or gratuity hasn’t already been added.  Some restaurants add a service charge for large parties, room service deliveries and for other situations. In these cases you do not need to tip.

So, for a quick summary of tips:

Airport curbside check-in - $1 per bag
Shuttle driver - $2
Taxi driver – 10-15%
Hotel bellhop - $1 to $2 per bag
Car valet - $1 to $2 to retrieve your car
Doorman hailing a taxi for you - $1 to $2
Housekeeping - $1 to $2 per night
Concierge – if service is provided, $2-$10
Restaurants – 15-20% (assuming a service charge/gratuity has not been added)

[via TravelSense]