Most couples are pretty confused on which, if any, of their wedding vendors to tip. And the truth is that it's pretty subjective, this tipping etiquette thing. You can find all sorts of advice all over the web, but rarely will it be consistent and give you a solid answer. It can be a little confusing.
When I bring up the subject with my clients (I always bring it up, because nobody likes talking about money), here is the advice I offer, based on my years of experience in the industry:
Tips are rarely expected, but are always, always appreciated.
Don't break your budget trying to tip your vendors. If you are early enough in the process, set aside a rough amount of money for tipping so it doesn't break the bank on the wedding day. Tipping should make you feel just as good as it makes your vendors feel.
Tip the people you would tip in real life (servers, car or shuttle drivers, beauty services, etc) at roughly the same amount you would if this weren't a wedding. (Most wedding questions can be answered easily if you take the word wedding out of it. "Hey, should I tip my servers?)."
Double check your contracts to see when gratuity is already included. Catering usually, but not always, includes gratuity on their bill (though clarify that it will also go to the serving staff).
Tips don't have to be cash. Whoa, right?! Everyone loves cash, but I can tell you I've received some really great, from the heart gifts from clients over the years as a thank you. From the bottle of my favorite whiskey, to all things skulls, to the whipping stick I got once (to keep the wedding helpers in line ... no, seriously!!), these gifts are all memorable, personal, and meaningful, and usually make me laugh or cheer.
If any of your vendors have not only met but exceeded your expectations, one of the best things you can do is leave a five star review for them on their site of choice (facebook is always a good option, but most of us also use The Knot and Wedding Wire to house reviews. Or send a card - handwritten love ROCKS!).
The bottom line IMO: show your appreciation in whatever way, shape or dollar amount feels right for you. However you care to show your appreciation of a job well done, know that gratitude is a wonderful thing that fills our hearts with all the warm fuzzies. We are working to make your day special because we genuinely WANT it to be amazing, not because we are expecting a tip.
Sometimes, after all this is said, I still get asked, "yeah, but really. How much should I tip?" Based on my experiences, here is what I usually see when tips are involved:
Photographer, Planner, DJ, bar - $100 - $200
Band - $20-$40 per band member
Officiant - $100 donation (if they are with a parish) or personal tip.
Lighting, Floral, Bakery - $40 - $60
Bartenders - discuss whether you're cool with them leaving a tip jar on the counter for guests to tip, or whether you want to work their tip into their fee. Generally - $150 - $300
Note that if you do plan to leave tips of cash or check, please have them ready to go in advance (at the rehearsal or the morning of), sealed in an envelope and labeled for the appropriate vendor. Hand them to your planner, or your designated person, to pass out as they day winds down.
Rock on, gang!