When doing items that are pre-sized like a coaster, watchband etc. is it best to put job origin on center and use current position?
There are a number of ways to do this. I often create a rectangle or circle of the size of the object, cut that out of cardboard, then place the object into the slot in the cardboard. If you center the artwork in the rectangle, then set that layer not to output, you can accurately place the cut on the object.
With objects that are oddly shaped, the camera feature is useful for this.