A friend of mine mentioned reading about cord/cable management recently. Spurred by this conversation, I decided to organize my cords over the weekend.
One method I tried was using these orange cord clamps from Home Depot. The nice thing about the clamps is that you can easily change the radius of the clamp. And they are easy to remove unlike cable zip ties.
I also used grocery ties (in green) for a tighter fit. They are still easily removable which is nice.
For more permanent cabling arrangements, I used cable zip ties (they look like this). The drawback of zip ties is that you have to cut them off with scissors and they are not reusable. There are three power cords in the picture: laptop, speakers, and external hard drive. You can also see a coiled gray ethernet cord.
Here's one more example. In the picture, you see cords for refrigerator, extension cord, surge protector, and lamp.