If you have many similar products, you may find it handy to copy your initial product listing rather than starting from scratch.
To do this, go to the Products page in your admin area. If you are using the Image view, hover over the image and click on the gray copy icon in the upper left. You will be taken to a new Edit page that allows you to change the product details for your new listing before saving it.
If you are using the List view, the copy icon appears to the right of the listing in the Actions column when hovering over the listing.