I’ve worked in the hospitality industry for more than two decades, which often leads to questions about the appropriate etiquette for tipping in hotels, resorts and restaurants.

Without a doubt, always tip. Many people depend on tips to earn a decent living. However, the tip should be earned, and it should be proportional to the service received. If you receive bad service, you should notify the manager but still leave a tip. If it’s exceptional service, tip more, and if you’re feeling really generous, let the person know that you appreciated their extra service, kindness or attention to detail.

How much to tip depends on a number of factors. The basic rule of thumb is 15 percent, before tax. It’s fairly common and simple in restaurants. Where it gets a little tricky is a hotel. This, too, depends on a variety of factors, including the type of hotel—bed and breakfast or luxury hotel? For the person who delivers your bags, the rule of thumb is $1 per bag but never less than $2. For the person who brings your car, $1 to $2. For the doorman, a smile and a “thank you” is all that is necessary, unless they go out of their way to do something nice for you. The same is almost true for the concierge. If they book a restaurant reservation for you it would be nice to tip $5 or so. If they find tickets to a show that were almost impossible to obtain, tip 5 percent to 10 percent of what the tickets cost.

And don’t forget the housekeeping team. They work so hard to clean a room, and because they’re rarely seen by the guests, they usually don’t receive the tip they deserve. Housekeepers should receive $3 to $6 per person per night for a luxury hotel. It’s nice to tip nightly because you’ll know that the person who cleaned your room will receive the money. It’s also acceptable to tip at the end of your stay. When I leave the tip, I always like to leave a note saying “Thank you” and a big smiley face. It’s a nice way to personalize the gratuity.