tipping independent vendors

I am having an independent videographer, photographer, and florist for my wedding. I'm trying to determine whether they require additional tipping and if so how much.

We're paying the videographer alot of $ and we figure that since he is independent, he will pocket most if not all of the $.

Our photgrapher is a friend of the family that will be traveling from Maryland to New York for this occassion (We're paying for his hotel accommodations). He is giving us a really great deal, but like the videographer he is independent and will probably end up pocketing most of the $. I was thinking about possibly getting him some sort of a gift to show my appreciation.
The florist is also a friend of the family and has already gone above and beyond expectations. I have already purchased her a $100 gift certificate to a favorite restaurant/bed and breakfast.
Can anyone help to shed a little light on my situation???