For those of us that have ever worked in a service industry, tips were at one point an important part of our income. Whether we worked as wait staff, cleaning staff, bell hops or even taxi drivers we relied on tips to supplement our income. The official definition of a tipped employee is 'anyone that earns more than $30 per month in tips'.

What many people don't understand is that there are actually two minimum wages - one for "normal" employees ($5.70 per hour in Wisconsin ) and one for tipped employees ($2.13 per hour in Wisconsin ). That pizza delivery driver or Applebee's waitress isn't even earning what we consider to be "normal" minimum wage; they rely on the tips of others to supplement their meager minimum wage and earn a living.

I personally have worked in a diner as a waiter, a pizza joint as a waiter and a pizza joint as a delivery driver, as a mobile Disk Jockey and in all four instances I was a tipped employee. Whether or not I could afford the roof over my head and the food on my table depended on the generosity of others. I know the joy of receiving an exceeding large tip and the anger at getting what is called "stiffed"; being left no tip whatsoever.

Now I'm not suggesting that you go tip crazy; those in the service industry must do their jobs properly to earn a tip. If your waitress is rude, for example, you probably wouldn't tip her or would tip her far less than what is acceptable. I've left a single penny if a waiter or waitress is especially bad; this sends the signal that I know I should tip but that he or she doesn't deserve one.

Likewise, if that pizza delivery driver is out in a blizzard and has to walk through snow drifts a mile high just to reach your front door, a bigger than average tip is probably in order.

The bottom line is that you should tip based on the performance of (or work done by) the service professional. Remember - if he or she wasn't there, you'd be doing it yourself. You need to determine the value of that service.

Which brings me to the big question: who should you tip and what is an acceptable tip? The following list compiled from several sources should help:

• Taxi drivers/Chauffeurs: 15% of fare
• Shuttle drivers: $2-$5
• Bell Hops/Sky Caps: $1 per bag
• Hairstylists: 15% to 20% of bill
• Restaurant Wait staff: 15% to 20% of bill
• Bartenders: $1 for beer or wine, $2 for mixed drink
• Take-out delivery person: 15% to 20% (minimum $2)
• Pizza Delivery: at $1 per pizza or 10% of the bill.
• Parking attendant: $1 to $2 when you drop the car off, $1-$2 when you pick it up
• Gas station attendant: $1 to $2 for pumping gas, $5 for pumping gas and checking fluids
• Room service waiter: 15% of bill
• Contractors (Foreman): $50
• Contractors (Worker): $30
• Sports arena usher: 50 cents to $1 per party if shown to your seats
• Clown at children's party: $15 to $25
• Dog groomer: 15 percent of bill, $2 per dog minimum
• Dance club DJ: $1 per song request, $5 to $10 if you want to hear it right away
• Wedding/Party DJ: 10% of the bill
• Massage therapist: 10% to 20% for a one-hour massage
• Tow truck operator (when locked out of your car): $5 to $10
• Hotel Maid: $2-$5 per day
• Housekeeper (personal, in home) 10%-15%
• Caddie: $40 per bag
• Maitre d': $20 if a special service is performed (such as getting you a table with no reservation when the restaurant is full)
• Coat Check: $1 per coat
• Restroom Attendants: $.50 - $1
• Lounge Musician: $1-$5
• Doorman: $1 (if he helps get a cab or with your bags)
• Hotel staff delivery to room (such as extra blankets): $1
• Spa services: 15% - 20% (to be divided up amongst all that provided you a service)
• Shoeshine Person: $3-$5
• Cruise ship cabin stewards $3-$4 per guest per day
• Cruise ship wait staff: $3-$4 per guest per day
• Tour Guide: $2-$5 for a 1-2 hour sightseeing tour.
• Furniture Delivery: $10 each person
• Hair stylist: 15% of the bill, whichever is more.
• Blackjack Dealer: $2-$10 or minimum bet at the table, after you're through playing
• Change Person at Slot Machine: 5-10% of your jackpot.
• Golf course bag drop: $2-$3 per bag
• Golf course cart return: $2 each (unless your bags/clubs are cleaned - then $5)
• Caddies: 50% of the caddie fee
• Forecaddy: $50-$100 total from the group
• Beverage cart: a $1 tip for a $3 beverage is typical

And most importantly, your favorite Op/Ed writer, $5 per "read" article