Some tips for both Crewmate and Impostor

1. (Impostor) (For Polus) If there are 3+ people in the office (not including you), you get out from eastern exit, 1 of the crewmates should see you get out, you go near the vent outside of lab, near the node task. Before going in, sabotage lights, vent back to admin, kill 1 of the crewmates and that 2 or more people will start accusing each other, and because 1 of the crewmates saw you leave the office before kill happened, it will also create an alibi. VERY sneaky tactic
2. (Crewmate) (For situations when impostor kills front of you and starts framing YOU for murder)So this is my side of the story. (Explain the things you done before kill happened, and talk about people who saw you doing these.), if impostor tries to outloud you, so other crewmates won't hear you. Shout back and say "LET ME SPEAK" Impostor will deny your story, but the crewmates seeing you doing what you said will confirm you. Ask the impostor for their part of story, he will give incorrect facts. Then say: "Was anyone near you to confirm your actions?" then other crewmates will agree with you and vote out the impostor. Easy
3. (Impostor) NEVER come out of the room where you performed a kill. Always escape to a vent. So this will prevent crewmates seeing you come out of the room that you killed someone. Vent back to a room nobody is in. And try to face to the opposite side of where the body is. For an example, if you killed someone in shields, vent to navigation, and don't go to the side where cafetaria is, head to shields. So people will think you either came out of O2 or weapons.
4. (Crewmate) When a sabotage happens, check the opposite side of where sabotage is fixed, since impostors most likely call the sabotage to lead the crewmates opposite side of where they killed someone.

If you guys have any more ideas, tell them in comments