You could have a session fee that includes print(s), quantity depending on size. Then you could get the client to review the images, giving you the opportunity to decide on the print included and sell more. I have a few examples in my studio that most won't find in a retail store, a couple example, prints made with canvas and prints made with an aluminum sheet rather than paper. I also suggest that 8x10 prints are for an album, an 11x14 print is for a bookcase or on a piano and then I suggest that a 16x20 and larger is for a wall. If you only show them small print examples, you will find that's what you will sell. There are many ways to show the clients just how this works but an LCD projector would help you get larger prints sold. Sometimes I will show a 40x30 print frame then have a 8x10 print inside it and the comment usually made is, "gosh, that's a small print!" Larger prints=larger profits. Why not strive for a good sized order? After all, it's your art and your time & talent getting the end result for your client.