Example:
You kill Yellow at navigation.
The most smart thing to do is to sabotage the reactor, and vent to the most nearby. Be careful, though, there are lazy crewmates who do not fix sabotages.
If you self-report, give fake proof as much as you can:
Red wasn't fixing reactor. He was headed towards Shields. The body was in navigation. He is sus.
If you have an imposter teammate and/or the crewmates figure out that you lied, SPECIFICALLY SABOTAGE LIGHTS. When a crewmate fixes lights and one is camping on the button, have your teammate or you kill them and lock Electrical doors. That will give you extra time for your cooldown and your sabotage. Sabotage Lower Engine and Storage, then sabotage Cafeteria on timing.
If you are caught venting, you can easily kill the crewmate that watches you. If it is multiple crewmates, sabotage the cafeteria, or where they are headed to and that will give you extra time for your imposter teammate to double kill them, leaving the last one to call a meeting and you and your teammate can give proof to vote them out. If you do not have a imposter teammate for this, sabotage where they are headed and call the meeting, saying that one vented, and say that the other crewmates are probably the other imposter(s) for vouching.
These are the strategies I rarely use to play, because they are on-the-top players in-game.
EDIT: If you get away with your kill by luck, sabotage the body environment or sabotage lights so the vision to the body is low, sabotaging electrical when the crewmates are done fixing lights. You need to fake lights, so they don't sus you. Come from the opposite direction of the body.