Sometimes a service charge or gratuity is already built in, so check with that first to make sure you’re not being overcharged. Other than that, here is who you might expect to tip and how much:
Hair and/or makeup artists: 20%
Waitstaff and bartenders: 20%
Delivery people: $5-$20
Parking and Restroom attendants: $1-$5 per guest
Your Officiant: $50-$100 or more if you are an active member of the church.
Most of your other wedding vendors will not be expecting a tip. However, you can still choose to do so for a job well done. For instance, if you were highly impressed with your photographer and felt that she could have been paid a little more, then feel free to slip him or her a $50.
Also, tips are not mandatory. 20% is generally expected, but you can leave less for poor service or more for exceptional service.