Angle isolation is all about not getting shot in the back. It sounds easy in theory, but in intense situations it can get quite tricky.
Novice
First thing to get started improving your angle isolation is to use cover for your back. If enemies can come from two different spots, you play close to cover, look one direction while your back is covered from the other.
Holding an angle

Peeking
When pushing, peeking into or holding an angle, we want to be covered for enemy peeks from as many positions as possible. The pictures below show two different ways of peeking sandbags.


Intermediate
Transitioning between spots
Improving upon the novice info, we now practice switching between which of the angles we are looking and which ones we are covered from. How exactly this is done differs from spot to spot. It is a good idea to visualize (and practice in an offline server) how you want to transition between the spots for every spot that you play.



