How much are you supposed to tip a guide?

I have been seeing a few geese flying in the afternoon around work.  I told Todd we should set up in the afternoon and try and run some traffic.  Todd got all the stuff together and went and set up.  I ran out right after work to meet him in the field.  I was like 60 yards from the spread when I see a line of 10 setting up a couple hundred yards out.  I hurry and jump down and watch.  I'm thinking, "They are headed right over me.  They're going to bust me, I better take em."  I jump up, miss my first shot, then hit two.  Todd stands up and looks at me with this look like, "Are you flippin kidding me?"  I felt bad, but a guys gotta do what a guys gotta do. Sorry Todd, but thanks for setting up.