Hide Your Bodies
Enemies will be put on alert and start a manhunt if they discover bodies (dead or not) lying around. A Low Chaos run doesn’t mean you have to be a complete ghost, but it certainly does help. If you’re running a build that’s low on health, you’ll also want to be extra careful in getting rid of the bodies as you wouldn’t want to get into a fight with guards that are on the lookout for you.
Consider dumping the bodies in secluded areas, or rooms where you know other patrolling guards won’t wander off to. Make sure to pay extra attention to patrol routes, and be aware of your surroundings at all times. On the other hand, if you do have to kill someone, at least make sure no one sees the blood just flowing around. Purchase the Shadow Kill ability to eliminate someone without leaving traces.