When drafting in modelspace, especially when you have a whole batch of drawings to be made, it makes most sense to keep the bottom left hand corner of your paper border set to 0,0,0 (x,y,z). Best practice would be to start your drawing out this way, but often that may not be possible as you are simply finishing up a drawing not originally drafted by you (or whatever such scenario, there are many). If this is the case you can easily move objects to the 0,0,0 point of your drawing.
The following commands are useful to accomplish this:
The ‘@’ is used to move (or copy) an object relative to the point you selected it to move from.
The ‘#’ is used when moving an object to an absolute coordinate, relative to your current UCS. So your object(s) will move relative to your current UCS 0,0,0 point.
The ‘*’ is used when moving an object to an absolute coordinate, relative to your WCS. As this 0,0,0 point will always be the same in every drawing, I prefer to use this point.
Some extra information can be found in the AutoCAD online user guide.