How to Kill a Person in Minecraft

Killing a Single Person

Find the person you want to kill. Make sure that they don't have a dog or friend with them.

Slowly follow the person. Stay around 15 blocks back and crouch so the person can't see your name.

Look at your surroundings. Make sure if the battle goes bad you have a good getaway, if you are near water put a boat there so you can easily get away, horses are also good alternatives when you are on land.

Attack. When you think the person is not expecting it or better they're is looking inside a chest. If you notice they're staring at a wall, that person might be in their inventory.

Eat a golden apple. Or have a potion of strength before attacking If you think you are not going to win.

Charge from behind. You have got better chances of killing someone that way.

If you have killed them, Make a quick getaway before someone notices and tries to get revenge on you.

Killing Multiple People

Watch them. Stay a good 20-25 blocks away from them. Make sure you are crouching.

Target one. And kill one using a bow and arrow. Once one is killed: ender pearl away.

Once you get close to them again. Kill one with a bow and arrow and ender pearl away.

If there are too many. Try to lure other people towards them, once the battle is nicely warming up start shooting people from a height with arrows.

Secretly Kill a Person

If a person is looking into a chest. Throw some poison at him and charge at him.

Ender pearl. Behind them and charge them down.

Shoot at them. From a distance, once you think they are low on health, ender pearl down, and finish them off by sword.

Walk around with a wooden sword. If they try attacking you switch to a diamond sword (which you will have in your hotbar, obviously) and finish them off.

Have your friend attack your enemy. Once the battle is nicely going, jump out of nowhere and finish off your enemy, if your enemy sees both of you they are going to run, if they see one person with bad weapons and swords, they are going to attack, not expecting you to come out of nowhere.

Simply. If you have a sword with knockback, try pushing them off a mountain or into lava.