Hello. This thread will be a contribution thread containing all the best duelist knowledge tips to building a good deck. If you wish to add your contributions to your thread with the knowledge in which you have learned by playing, feel free to do so.

NOTE: Not all contributed tips will be added to this post.

* The first thing to do when deciding to build a deck is what theme you want your deck to be. What do I mean by theme? I of course am talking about the deck's central purpose. For example, Exodia decks rely on getting all 5 Exodia pieces into your hand. So for that certain deck you have to have good drawing power.

* After you decided what type of deck you want to make, research support cards for that deck's theme. For example, a good support card for a Zombie deck would be Pyramid Turtle. It allows for wall defense as well as monster searching. Its a great 2 in 1 deal. Note: Staple cards are optional to add to your deck. I find that most of them work well with any sort of deck theme but you may have a different view. Avoid broken cards if possible.

* Now that you have decided which support cards to use, its time to start adding the main parts of this deck in which it feeds off. For example, One Turn Kill decks rely solely on cards like Cyber-Stein and Megamorph to deliver a 1 hit kill with a monster that has more attack points than what lifepoints are left of the opponent. Avoid broken cards if possible.

* After you have built this deck, be sure to do trial runs to test it out. If some cards aren't working well with others you can always replace them with more efficient cards.

Yu-Gi-Oh! Dictionary
Staples - Cards in which have great effects and work with most decks. Most consider these to be without flaws.
Broken - When someone refers to a card as broken, that may mean that its cost can cause you too much trouble to use or that its a useless card in general.