haha if i start em from the finish i guess they are already there. some people say start em from the finish point of your drag so they can run from weaker to stronger scent.
weaker should be the oldest so that is where you start the track which is where you first started laying it down....
if you want the dog to learn the direction then lay a longer track and come at it at an angle about the middle of the drag and see which way he will take it.