I would say the best method to figure out how GUIDE works is to break points in the OpeningFcn() section of your GUIDE GUI. At this point you can peek at the handles structure and see the order inwhich things were created. As you would do for any struct the order is basically the same order inwhich you plopped it down in GUIDE. If you are looking to go away from GUIDE but use GUIDE to layout you can see my submission here
on how to use GUIDE to help layout a GUI such that you can try to recreate it.
