I agree that you can publish the sample work on your blog first so that the client can't say that it's their property -- or at least they will be turned off by the fact that it's published content. I take photos and always send an impossibly small image so that the client can see the image but not steal the quality. I used to watermark images but found that client/thieves were simply cropping the watermark out. Yes, I could have chased the copyright, but the client/thieves know you won't think it's worth it.
Join in and write your own page! It's easy to do. How? Simply click here to return to Work From Home Scams.