One of the biggest challenges in home decorating (at least for me) is figuring out the paint color. A 2"x2" paper sample in the hardware store does nothing to help me know if I am going to like that color when it appears on my wall. Apparently, I am not the only one with this problem.
Lowe's has developed an ingenious product, Spot On, that allows you to temporarily put a sample on your actual wall -- without buying the gallon of paint or even without ruining the current paint that is there. The Spot On kit provides you with all the materials to paint special temporary decals that you put on your wall to gain a much better idea of what the paint actually looks like in your home. It's still small, but it is giant compared to the paint chip and it is actually paint, not paper -- all good things.
Think about how you can allow your clients to sample your product before they must fully commit. Can you offer an introductory session before a full course? Maybe you can have a reduced price for a taste of something? Can you provide just a piece of your product/service to allow customers to authentically test it? I think Lowe's idea is spot on, and a great model to follow to make the buying process less stressful.