We tipped our photographer, catering staff, hair and make up girls, and the band. We gave money ($50-$100) in an envelope with a thank you card and a handwritten note. For me, the % amount just worked out to too much money on top of the services.
I was told to tip vendors who work for a company, so if your photographer is independent and works for themselves a tip isn’t required. If you do tip I was also told 10-15% is average, but that can work out to a lot of money so I kind of like what people like Amanda did and go with a gift card.