Do not self-report more than 3 times in a row.
It will make you look sus because by not self reporting often, each player will report a dead body at a consistent rate, which would look normal.
Sabotage while faking tasks
You don't have to move while sabotaging, plus this gives you an alibi to say that there was a sabotage you were trying to fix. Moving while sabotaging is also a great strategy, however keep in mind that this is another option.
Avoid killing in high-traffic areas
If you do so a crewmate is likely to find the body while you are trying to get away from it.
Fake visual tasks if possible
This gives you an alibi to say that you did the task that you faked if visual tasks are on.
Critical sabotage right after killing
This is key to winning since it makes use of two impostor abilities, kill and sabotage without them being mutually exclusive. It allows you to wait your kill cooldown. On the Skeld, if you kill on the right, sabotage reactor. If you kill on the left, sabotage O2. On MIRA HQ, sabotage O2 right after killing in launchpad, balcony, cafeteria, or reactor. When killing in greenhouse, balcony, or cafeteria, sabotage reactor. On Polus, it is possible to direct crewmate away from the body by sabotaging seismic stabilizers when killing at the bottom of the map, however this is usually unnecessary due to it being a large map. Same for directing crewmates from the edges when sabotaging avert crash course.
Sabotage when there is one more crewmates than impostors
This allows you and sometimes your fellow impostors to wait their kill cooldown until one of you can make the final kill and win the game. The crewmates will try to call an emergency meeting as soon as this happens, and sabotaging prevents them from doing that. Fix Lights is the most preferred sabotage for this situation, since one of the impostors can flip the switches off, hindering the crewmates from solving the sabotage. Reset Seismic Stabilizers on Polus and Avert Crash Course on The Airship also can work, but often requires the impostors to fake fixing the sabotage.
Source: https://www.reddit.com/r/AmongUs/comments/qboa74/insanely_helpful_impostor_tips_in_among_us_this/