Tipping can be an important line item in a family vacation budget. Travelers are often eager to show appreciation for exceptional service. But how much and when to offer this symbol of gratitude can be perplexing.

Consider this input from travel industry experts:  

Adventure travel.

On any adventure tour, a good guide can make for a great trip. “I like to tell guests that if you feel your guides played a major role in your enjoyment of the trip, you should direct a gratuity to the trip leader. He or she will distribute it fairly and evenly to the crew,” advises Karen Johnson, a manager for Holiday River Expeditions. “An average tip is $10-$20 per guest, per day.”

“At Austin Adventures, we encourage guests to tip what they feel is appropriate given a guide’s performance on a tour. We offer $15 to $25 per day, per guest, as a guideline,” explained Austin founder, Dan Austin. “We also note that tips are a significant part of a guide’s income.” When booking an adventure trip, ask in advance for tipping guidelines and determine whether cash is required or credit card payments are possible.

Contact: www.BikeRaft.com;  www.AustinAdventures.com

Small Ship Cruising.

“Typically, at the end of a cruise there is an opportunity to provide gratuities to the guides and crew,” explains Todd Smith, Director of AdventureSmith Explorations.   “Gratuities aboard small ships are often pooled among crew members. Tip pools sometimes include officers and guides, while others do not. Some ships will take credit cards while others prefer cash or checks. Check to see if gratuities are included in the price of the voyage. If not, 5 to ten percent of the rate paid is an average amount to consider setting aside to show gratitude for superior service. ”

Contact: http://www.adventuresmithexplorations.com/)

Hotel stays.

The American Hotel & Lodging Association (AH&LA) recommends offering the bell staff one to five dollars per bag when escorted to your room. Leave a tip of one to five dollars each day for the housekeeping crew (or more if the kids have created a little havoc). Need something extra? Offer two dollars for one item delivered or five dollars for more. No need to ante up for the replacement of a broken hairdryer or a missing light bulb. In the restaurant, tipping servers 15 to 20 percent is the norm.

“Tipping the concierge $20 and up, depending on their level of service is good practice,” suggests Richard Wales, Director of Operations, at The St. Regis Aspen Resort.

“They are the ones who will be able to get you the most coveted dinner reservations around town.”

Contact: www.AHLA.com; www.StRegisaspen.com.

Airport travel.

Experts suggest offering car rental shuttle drivers $2 to $4 per bag if they provide bag assistance. Plan for $2 to $5 for help from a Skycap, offering the higher amount for heavier bags or late arrivals. Should you or someone in your party need wheelchair assistance, consider a tip of $10 to $20, depending on the time and circumstances involved.

Traveling in Europe.

“Tipping has become commonplace for hospitality service around the world, and is a universal sign of appreciation for good service” says Steve Born, Vice President of Marketing for the Globus family of brands. “As a guideline, we suggest the equivalent of two dollars in the local currency for our Monograms tour guides per outing, per person. For other services, like restaurants and taxis, we suggest rounding up the tab by the equivalent of a few dollars. Typically in Europe, restaurant tips are left in cash and not added to the credit card.”

Contact: www.GlobusJourneys.com;  www.monograms.com .

Your fishing guide.

It is customary to tip your professional river fishing guide or boat Captain. And like many other services, a 10-20% gratuity is most common.

"Most fishing guides are dedicated teachers and fish freaks who would rather be on the water helping you than most anywhere else," explained Joe Dilschneider, the owner of Troutstalkers, a Montana-based fly-fishing outfitter. "A vast majority of them will work hard to help you have a successful outing. Just remember; success isn’t always narrowly defined by your catch!"

But like any service-oriented profession, personal rapport and compatibility matter and there is definitely a broad spectrum of personality types and talent out there in the world of fishing guides.

"If you feel that your guide put forth a solid effort to help you have and enjoyable and successful day, then tipping them generously will feel good and they will usually show you their gratitude and welcome you back in the future," explained the Ennis, Montana-based pro.  "A connection based on shared adventure, and a love of the game is after-all what most guides really want from you. That's where the real payoff is. If however you are disappointed with your experience, then you shouldn't feel obligated to give a generous tip. Your guide will certainly notice if your tip is unusually small... or big. Hopefully it will encourage them to consider their own professional performance and always strive to improve!"

Note: When unsure of how much or when to offer a gratuity, it never hurts to ask. Many tour and cruise operators provide suggestions and guidelines in pre-trip planning documents.