My main item that I sell is dishcloths. I have made a ton of them, and sold many.
Here are the colours I currently have in stock. (back to front: black, rainbow, burgundy/cream/navy, pink varigated, blue/white/yellow, rainbow pastel, salt and pepper)
These are the dishcloths EVERYONE knits. The easiest pattern I have ever used.
I also have awareness ribbon cloths. I got the pattern Here. Its pretty easy, just knit and purl stitches, but I have a hard time remembering to do so at the right times. The pink one is much closer to being done. A little more detail here. Once again, you can tell I hate weaving in ends!