Corel Photo Editing :: Making Object Out Of Image?

So let's say I want to use a picture of a coca-cola bottle from an image I found on the internet, or I take a pic of one... what is the best way to cut-it-out?

1) For instance, sometimes, the object is cut out of a white background and I want to use it on a black background... leaves a nasty outline :( - maybe its easier to take a pic of the object on a black background (which is what I usually do - but I don't feel like getting the camera out - besides, I then almost always need to touch up the photo)

and 

2) how do I easily smooth the edges if a use the colour wand? before or after cutting out (Copy to clipboard)?