I managed to work with the new Safe Area layout guides and maintain backwards compatibility with iOS 9 and iOS 10: (EDIT: as pointed out in the comments by @NickEntin, this implementation will presume there is a status bar present, which won't be true in landscape on the iPhone X. Resulting in to much space to the top (20 points). It will run perfectly fine however.
E.g. if you want a view to be 10 points below the status bar (and 10 points below the sensor housing on iPhone X):
File Inspector
and enable the safe are by checking Use Safe Area Layout Guides
.>=
(greater than or equal) constraint, constant 30
(30 because we want 10 points spacing to the status bar which is 20 points high) and priority High
(750).=
(equal) constraint, constant 10
and priority Low
(250).The same can be done for a view at the bottom (and for leading/trailing or left/right to the Safe Area):
File Inspector
and enable the safe are by checking Use Safe Area Layout Guides
.>=
(greater than or equal) constraint, constant 10
and priority High
(750).=
(equal) constraint, constant 10
and priority Low
(250).