Ever want to make a Halloween costume that all your friends can wear? No problem. With this guide, You can make this possible! Read on...

[edit] Steps

First you must get all of your friends, say around 10, together at your house an hour before the trick-or-treating starts.
Now you all must wear black ski masks, Due to the word "mafia" people now stereotype them to be thugs in ski masks. Put on a bunch of ragged cloths too. Perhaps dad's work clothes...
To spice up the costume you can add weapons. FAKE weapons. Have someone hold an AK-47, another have time bombs in his jacket, Etc. Use your imagination.
Make sure everyone has a backpack,but a hard guitar case works better. That's for candy- and it goes real well with the costume! Put some satchel charges on it to make it look dramatic.
Go trick or treating, try to make a mafia phrase along the lines of "You wanna dance pretty boy, No? Then give me some CANDY!!!!!!!" Make it sound cool.
Have fun!

[edit] Tips

When walking down the road have a bit of a march going on to make it look more organized.
Don't point the guns at cops.
Have fun with it!
If you want to have the fake 5 on 5 mafia battle make it look real! It gives off the fear in Halloween.