Firstly change your skin to anything! A few fries, an animal or more! Then write in chat this command without inverted commas "/give @p minecraft:command_block" which will give you an item called a command block which is a block a lot of map creators use. Put the command block down and write inside the command block (again without speech marks) "/give @p minecraft:skull 1 3 {SkullOwner:<username>}". So if you wanted to get my head you would type /give @p minecraft:skull 1 3 {SkullOwner:ChoudCurry} .
This video is by OMGcraft[img=]command block[/img] All credits to him.

Hope you got it!




Here are a few of the commands if you didn't understand the text!