Airport/hotel baggage handlers: If you're lugging around more than two pieces of luggage, let one of these guys help you out. Depending on the size of the suitcases, tip $1 to $3 per bag.
Courtesy shuttles: A number of hotels offer free shuttle service to and from Midway and O'Hare airports. You're saving a ton of money, so why not be generous with the driver who has to deal with that monotonous job all day long? Shell out anywhere from $5 to $8. Same goes if you're traveling in one of the paid shuttles; tip at least $5.
Concierge: The concierge's job is to be on the pulse of what's hot in town. The job also requires him or her to fulfill special requests, including reserving dinner reservations, theater tickets and spa appointments. Now, if you happen to go over to the concierge desk and inquire about the best sushi restaurants in town, they're good about ticking a few off from the top of their heads. Tip a couple of bucks. If you have the person look up directions or make a few phone calls, tip no less than $5. If you have an elaborate plan to secure hard-to-get dinner reservations or tickets (e.g. Bulls or Broadway on Chicago tickets), then the concierge is expecting a minimum of $20.
Gourmet and coffee shops: You'll find that more of the upscale and "hipster" shops have tip jars next to the cash register. Here's when you tip: If you place a complicated coffee order, tip the barrister $1. Those ordering a simple cup of joe or tea should not feel obligated to tip.
Hotel bars: Cash is always king, but hotel bartenders (and restaurant servers) are the most understandable when you tip them by credit card (or room charge). Beer and wine drinkers should tip $1 for each glass, while cocktail enthusiasts should pony up a bit more for the extra effort. That's anywhere from $2 to $3 per drink.
Hotel doormen/bell staff: Should you tip them for opening the door? Our official hotel tipping guide says no. A smile and "thank you" are good enough, however, if you require them to hail a cab, then shell out at least $1. Several hotels offer dog walking services such as Trump International Hotel & Tower Chicago. The service is $15 for a 20-minute walk (for dogs 25 pounds or less only) and an extra gratuity for the bell staffer is at the guest's discretion.
Maid service: Here's a great guide to tipping housekeeping.
Nightclubs: If you plan on clubbing while visiting Chicago remember one thing: Chicago is not Las Vegas. The average doorman is supposedly not allowed to accept tips; he risks losing his job if he accepts cash for allowing patrons to skip the line, etc. If you want good service at a busy bar, tip at least $1 every time you order. Those ordering bottle service should tip as though they're being served at a restaurant; a minimum of 18 percent gratuity. And if there is a bathroom attendant, there's no need to tip unless you use the amenities (hairspray, lotion, grooming supplies, mints). If you do, tip at least $1.
Restaurants: Is this a business trip? Always remember that tipping is not optional, it is mandatory. For casual gatherings, at least 18 percent is expected. In Chicago restaurants, if you have a party of six or more, the gratuity is included in the bill.
Hotel room service: If you get delivery at home, it's pretty much the same. Tip at least $2 to $3.
Spa services: Tips are pretty much the same across the board. Hairstylists, manicurists and massage therapists get at least 15 percent of the total bill.
Taxi cabs: Cab drivers in Chicago can be a point of contention, especially with visitors to the city. Always remember that you can charge your entire ride to a credit card. You can also tip on the card (some drivers will try to hustle you and say no), but if you have a few spare dollars, tip with cash.
Valets: A $1 tip is sufficient.