These are a few of the different tournaments that I have seen while judging :
Traditional Format - Players follow the Traditional Format Banned/Restricted list.
This follows the Traditional Banned/Restricted list and allows players to use a single copy of all the banned powerful cards again.
Booster Draft - Players are given "X" amount of booster packs and make a deck from those cards.
Players can use all the cards that they pull in their booster packs. To make this fair, all players receive the same boosters. ( for example: each player would receive 1 LOB, 2 MRD and 2 SRL or "X" amount of the same booster pack)
Arc Format - Players are only allowed to use 2 of each card.
This follows the nomal Banned/Restricted list and means thats any cards that are restricted to 1 cannot be used and cards that are best in 3's become less usefull.
Mega banned - Any card on the Banned/Restricted list cannot be used.
Like the description says, no cards on the Banned/Restricted list can be used, which means that you have the challenge of making a deck without some of the most powerful cards in the game.
Creature Feature - All monster cards used have to be of the same type.
This follows the nomal Banned/Restricted list, but has the restriction of having to use monsters of a single type.
Also similar to the above, I suppose that you could also have a restriction on having to use all monsters of the same attribute, however I have yet to see a tournament with this stipulation.
All of the above tournaments have worked well and as far as I am aware, there were no problems when running these tournaments.
I think that the players really enjoyed the change from the normal formats that are run and liked the challenge that the stipulations gave as it made them have to think more in order to do well.
Just remember to advertise well in advanced in order to allow players time to prepare for such events that are different from the regular format tournaments.
I hope that this helped and good luck.
Andy Cummings
Rules Knowledge - Yu-gi-oh!: Level 2
Player Management: Level 2
Tournament Organizer: Level 1
UK Nationals Judge - 2006 - 2007 - 2008
UK Pharaoh Tour Final Judge - 2006 - 2007
UK Gen Con Judge - 2007
World Championship Judge - 2008