Too much information
Among Us is all about information warfare, really. Who was where, what were they doing, what happened, why did it happen, etc. So you need all the information. You need an extra pair of eyes. You need friends.
Yes, if you play Among Us with real friends, you can simply talk to them to know, well, everything. When they die, who killed them, where they were, what they saw. All of it can be yours, with friends.
Honestly, knowing at all times just what one extra player is doing and looking at can massively change the nature of the game. In an unfair way, mind. But that's why this is called cheating.
A man on the inside
The best part about cheating, of course, is that you swear a vow of secrecy with whomever you're collaborating with. And they will not suspect you for a moment.
Yes, if you are the imposter, and you're sat next to a dear friend you've been colluding with, they will not suspect you until it's too late. Just make sure to kill them last.
If you don't have friends, a non-cheaty way of getting away with this is ensuring to hit Play Again after every match, and bonding with one or two of the players you're hanging out with.
Smash that emergency meeting button
The nice thing about cheating and chatting is that you will know the instant one of your friends goes down, and if you want, you can just smash that emergency meeting button before anyone even knows that someone is dead.
And of course, your dead pal can immediately tell you who did it. Though, immediately smashing the meeting button and accusing someone is a pretty risky game, if we're honest.
Once you smash that meeting button, come up with a good excuse, claim you witnessed it, or at least give it a few seconds. If they figure out you're a cheater, it's all over for you.
As good as cheating, honestly
Have you ever started up your own lobby and edited the settings? Honestly, this is a great way to win a game with a bit more ease.
You can massively cut the vision distance of all the crewmates, and have it so the imposter is just a devious supervillain. Everyone in the lobby will be able to see the changes of course, so your fellow players might just decide to jump out.
But there are a few settings you should keep even. For example, imposters and crewmates should certainly move at the same speed. But a gang of three imposters with giant vision ranges will lead to a fascinating game experience.