A Screens Camera to See A Main
Consider picking up a sniper rifle or Guardian if you're going to play behind A. This camera will show you when they're coming, giving you time to setup and peek.
Defense B Site Setup
This setup dramatically slows down the attackers push on B Site, gives your team a ton of important information, and buys time for them to rotate if the attackers for their way through.
A Lobby & A Main Camera from A Heaven
Strong starting camera that shows enemies outside A. Go into this camera immediately because it is typically shot very quickly.
Middle Market-Side 1-Way
Very strong mid defensive 1-way against peekers from Market.
Pretty easy and standard A Site setup. Early vision, distraction with the camera. Open to a Lower rush. it that happens just stall until your teammates can rotate to you.