Gratuities are for those who have preformed their duties and have done them exceptionally well and above your expectations, they are usually provided at the end of the night (usually in cash). Most tips are at the discretion of the bride & groom. I can tell you from experience that when a gratuity is received or presented no matter what amount the vendors are extremely happy.
Alternatively, you’d also be surprised how far a thank you card, testimonial for a website/portfolio, review on their services on a website, or perhaps some photos from your wedding goes! This is something you could do to thank your vendor for a job well done that they might just appreciate more than a gratuity.
Here are some vendors you might want to include into your budget.
Caterer – Usually this is built into the contract price, usually 15-18%. Unfortunately if they do not live up to expectations you cannot take back the gratuity you will need to speak to the vendor after the wedding.
Makeup Artist/Hair Stylist – Depending on the services and how early they had to come in, a tip of 15 – 20% is typical.
Limo Driver/Transportation – Usually a tip of 15 – 20% is provided, sometimes it is included in the contract, so read your contracts.
Wedding Planner – Any gratuity is at the discretion of the bride and groom.
Photographers/Videographers – Gratuities are normally presented but if your photographer/videographer went above and beyond what you had expected, typical amounts can be anywhere from $50 – $100 and more.
Ceremony Musicians – Typical amounts range from $50 – $100 depending on the amount of musicians and length of play.
Officiant – Any gratuity is at the discretion of the bride and groom and can range from $20 on up. Be careful when tipping if you are using a religious institute as sometimes it would have to be in the form of a donation to the church and not to the priest/minister/reverend etc.
DJ – When a DJ has done their job right, no one wants to leave! They most certainly appreciate any gratuity but it is not expected, typical amounts range from $20 – $100.
Floral Designer – A gratuity is not expected but is very much appreciated. Typical amounts start at $20 and go up.
Cake/Baker – As with the florist a gratuity is not expected by much appreciated, and is at the discretion of the bride & groom.
Remember most of the time it is not up to the contract, but to you as gratuity is a thank you for exceptional services not a must, nor is it expected. Very much appreciated but not expected.
(source)
(Charlene from 
