For first sessions with riders with previous experience I like to do a general evaluation. I ask them where they think they are as riders, what their experiences have been, what type of training their horse has had, what they know and to show me.
It helps me to see where any holes may be in training and where there is room for improvement.
I also like to set goals at the end of that session. If your trainer knows where you want to go, it's much easier for them to help you get there.
Life is like a camera. Focus on what's important, Capture the good times, Develop from the negatives and if things don't work out, Take another shot.