(I'm sorry for the long post, but I hope that you at least try to read through it before voting against me! )

Oi, guys!
Welcome to my (not so official) lesson on how to perfect a deck. One might think that something so basic would rather be a lesson for the Slifer Dorm, but in all honesty, building a consistent and well rounded deck is something only the best truly master. I will also have a special look on current tournament happenings and the infamous and hated Meta-Game. So let's get this tarted:

1. Choosing an Archtype/Theme:
Even though this sounds like out of the anime it is really important that you actually choose an archtype or a certain strategy and build your deck around that. Mostly because you get plenty of support cards for your monsters and you can get your plays off much smoother and faster.
A little example: Wind-Up Shark is a very usefull card, due to it's ability to both increase or decrease its level and could be used in many XYZ-heavy decks but it unfolds its true potential when used in a full-fledged Wind-Up deck, because he is much easier to summon and provides you the possibility to go into essential cards like Zenmaity.

Now, you have to ask you an important question: What archtype to choose and build your deck around? Basically, you need to choose whatever you really like. If you are into Synchros you have things like Blackwings to refer too, if you prefer the XYZ-monsters you can always recur back to newer sets such as Wind-Ups. If you don't even like any of them you still have plenty of other deck types available. Be it Fusions (e.g. E-Heros) or maybe even plain old Special Summoning without relying on an extra deck (e.g. Machina).
There is something for anybody and once you know what you really like to play it is easy to choose an archtype for you.


2. What cards to put in?
Once you choose your play style the next big question pops up: What cards to use? There are plenty of support cards for every archtype and there are even more cards that are often called "staples" and used in every deck, so what do you really need in your deck and what could be somewhat expendable?

2.1 Monsters:
The monsters should always be set up in a way that they help you to get your trump cards out FAST and do not clog up your hand. Lets assume you are playing a very XYZ heavy deck. You would want monsters that can be summoned very fast in bigger numbers so you can immediatly go into your XYZ-trumpcards. What you don't want are monsters that are difficult to summon and stay on your hand for quite a while because they just aren't usefull to you. Even if you have high rank XYZ monsters, you wouldn't want high level monsters that require tributing in your deck, because they would be difficult to summon and would be so called "dead-draws". Instead you can recur to cards as Star Drawing or Gagaga Magician to summon high rank XYZs much easier and basically without loosing as much cards.

Also you should not use monsters that are only usuable in very specific situations. Lightsworn Beast Wulf is a good example. His only use is if he is milled but if you draw him, you will have no use for him in your hand and your draw was no good for you. You should avoid cards like that as every single card in your deck should basically always be of use.
Gorz is yet another example: If you use many backrow cards you can't use Gorz, because you can't summon him as long as you control any card.

2.2 Spells:
Spells are probably the most important support cards in your deck. Every archtype has it's own set of spells that take the deck to a higher level. Wind-Up Factory greatly increases the speed of a Wind-Up deck and gives you OTK potential. Just as there are good support cards there are also plenty of bad ones that aren't really usefull at all or only in a very special situation which is very rare to happen. In this case the same rule as for monsters counts: Only use cards that will always be of use to you!
To complete the the spells in your deck there are plenty of so called "staples" Every deck needs a few of them, although you never really need all of them. I think everyone agrees that Monster Reborn, Dark Hole and Heavy Storm are always usefull but then again only a few decks can really make use of cards like Pot Of Avarice. You wouldn't want to use that in a Chaos Dragons deck, as you actually want monsters in your graveyard, whilst it can save your life when playing decks like Constellar, where you actually want to recycle your monsters. So you need to take a good look at your deck: Do you want monsters from your graveyard back in the deck, or do you actually want them in the graveyard? Do you need a thinned-out deck or a slight speed increase by drawing? If you are not sure: test your deck with and without the card and see if it ever was really usefull to you or if it eneded up on your hand without beeing used.

2.3 Traps:
These are the most important defensive cards in the game. Traps can destroy whole decks and secure you a win immediatly. Macrocosmos kills popular decks like Inzektors and Dark Worlds, rendering them helpless and giving you plenty of time to build up your game and go for the win. But can your deck really use Macrocosmos or do you need the graveyard for something? If you don't need the graveyard at all, Macro is a card you really should use!
Other very popular cards are the Solemn Brigade. Basically everyone uses 2 Warning and one Judgement, but that is a very dangerous combination. If you happen to use Judgment early in the game it will take a LOT of LP from you. Just imagine it takes 4000LP from you and you still have 2 Warining in your deck. You can still use one and go down to 2000LP but there 2nd Warning will be useless from that point on. So, do you really want to risk using something like Judgement? Or should you maybe rely on other cards that achive a similar effect? Instead of Jugdementing an XYZ or a Synchro you could instead use something like Compulsonary Device, which send the monster back to the Extra. Of course your opponent can then use it again later on, but in that very turn he used at least 2 cards to special summon it and you will just kick it back, making him use another 2 or more cards to bring it out again. He will go -2 instantly and you will still have your LP unharmed.
Another popular card is Starlight Road, which is always usefull but really shines in certain decks. If you play a deck like Dino-Rabbit you will mostly only focus on getting one Evolzar out and using that one to block of your opponents plays. Starlight Road won't be that usefull, mainly because you only have a single monster and you can get it back pretty easily. If you play something like Chaos Dragons or Wind-Ups you will love that card beause many times you will summon a lot of monsters in a single turn, so Starlight Road protects you from Mirror Force, Torrential Tribute or even Dark Hole. Just imagine the impact it has on the game: You opponet uses his only Dark Hole and you counter with Starlight Road, negating his powerfull Spell and summoning a very Powerfull Monster to your side of the field!

So again: Look at your deck and think about how likely certain situations are to happen. Will you ever have many monsters out on the field or do you rely on a few single trump cards? Can you sacrifice LP because the rest of your defense is so good or is your deck to offensive and you need to protect your LP?


3. Side Deck:
A Side Deck will save your behind more times than you can count, if build correctly. Basically it is your allround weapon against every popular or dangerous deck. If you play Mermails, you know tht Macrocosmos will be dangerous to you, so you need to put cards in your Side Deck that can work around such problems e.g. Mystical Space Typhoon or Dust Tornado. Basically there are 3 simple and euqally important rules to follow:
1. Make it versatile! You need to have cards against every big deck there is, because rendering your opponent helpless is the best strategy. Shadow Imprisoning Mirror or Macrocosmos kill Dark Worlds, Inzektors and even Mermails easiely!
2. Protect yourself! If you know your deck or strategy have a certain weakness against certain other decks, put cards in that combat that weakness! Knowing your own weakness means you can protect them and not let the opponent hit you there.
3. Side against what your opponent Sides! Sounds weird you say? It is essential I say! If you know your deck well you will know what cards can stop you and what will be sided against you. What you need to do is side against cards that are sided against you (yes, sounds confusing). If you play Dark Worlds you just know that there is a Macrocosmos waiting for you in your opponents Side Deck, so you will protect yourself against that my either using Royal Decree (if it doesn't conflict with your other cards) or maybe just putting in an extra MST or even Dust Tornado! Your opponent will be relying on his siding and you will destroy his siding!


Also a final piece of advice: DO NOT use a Net-Deck. Only because someone won a tournament with it does not mean you will too. Everyone has a diffrent playstyle and you need to build a deck that fits your very own. I can promise you that you won't be succesfull with a net deck, at least not at high level competition.

nice work

WOAH nice job dude