How do you turn on creative mode in Minecraft?

Answer 1

If you are making a world then:

At the Main Menu press: Singleplayer -> Create New World -> Gamemode: Creative.

If you already have a world then:

(If cheats are enabled) /gamemode c or Press 'esc' -> Open to LAN -> Allow Cheats: ON -> Start LAN World -> Go back into game and type /gamemode c

Note:Opening your game to LAN will not allow random players to join your world, if someone else in your house is using the internet and are searching for LAN worlds on their PC then they might be able to join (but to be honest I have played loads of LAN survival with my friends and you can't actually see the world unless you have an amazing internet connection, we usually have to type in the port).

Happy Minecrafting!