While it is easier in the long run to take pictures with a solid background, most often I find I am snapping a picture like this--on my not too attractive ironing board cover.
This picture is my latest bamboo/cashmere scarf. I delivered it last night to the fellow who last gave me 10 cashmere sweaters.
I have discovered, however, with not too much trouble, I can doctor my pictures. Actually, I quite enjoy the process. It is much like playing a computer game except in the end I have something to show for the hours spent. The picture above is still a work in progress. I believe I can make the edges of the cloth a little smoother.
I am using the program Photoshop Elements 2 (quite an old version). You can now purchase Photoshop Elements 6. Corel puts out a program called Paintshop Pro which is quite similar and actually comes with the newer computers. Here is a site that sells both. The older versions are surprisingly cheap, and even the latest versions aren't very expensive.
I have yet to master "layers" which would make it much easier to alter the backgrounds. I think part of me likes enlarging my picture until each pixel is a 1" colored square and having the power to alter a picture pixel by pixel.
One important tip: Always save the original picture, and do all of your changes onto a copy.
I'd be interested to hear other people's experiences.