Instructions
Search every room thoroughly to find any hidden chests. Use the right thumb stick to look around the environment to ensure you don't miss any chests hidden in hard-to-see alcoves or on top of platforms. Go down every hallway and check around every corner, to make sure you don't miss any chests.
Return to chests you could see but not access earlier in the level. Some chests can only be accessed later in the level -- after you have unlocked a certain door or gained a new ability. Don't forget to return to these chests after you have progressed further in the level.
Determine what abilities War possesses that would allow you to access a chest that seems out of reach. Some chests act as mini puzzles that require you to combine several of War's abilities to reach them. Think about how you can use War's "Crossblade," glide ability and inert bombs to gain access to a chest.
Replay through a level, if you miss some chests the first time through. The end of the level recap will show you how many chests you found out of the total number available. Go back through the level a second time, and search more thoroughly.