For Killer, you want to choose the perks that upset your opponents the most - As this will make them act irrationally and make the game better for you - The Children Survivors you will be fighting will have no idea what to do when you're coming at them or wall hacking them with Ultimate Weapon

Ultimate Weapon
Always pick ultimate weapon, is the best perk in the game

Eruption
Bring Eruption Too, its great for making sure the game goes on long enough to kill

Lethal Pursuer
Lethal Pursuer is a must have for an good player, it lets you kill your enemies quickly

In order of strongest killers:

1) Alien
2) The Knight
3) Skull Merchant
4) The Hag
5) The Twins
6) The Blight
7) Chucky

To win the game properly, you must tunnel - Tunneling is when you hard-focus on somebody and don't hunt anyone else, this is the objectively correct way to play the game and you should always do this - Don't listen to neighsayers who will try and tell you its toxic or unfun to just destroy survivors one by one when you tunnel them out of the game

Camping is the second best strat, but don't get too close, or those pesky survivors will unhook themselves - Just push their friends away one b one and then smack your victim a bit - Its their fault for bringing dead-hard, Decisive strike, or a flashlight for getting tunnelled and camped out of the game