When building a Deck, it is important to remember your theme. What is your Deck supposed to do? Play a lot of WATERmonsters or Warriors and make them more powerful? Tribute Summon a lot of high-level monsters? Collect all 5 pieces of Exodia? Make it so your opponent does not draw many cards? These are all good strategies, but no Deck can do all of them. You need to pick 1 theme per Deck.
Think about your strategy when making your Deck. For every card, think to yourself: Is this important for my strategy for this Deck?
Just because a card was helpful in the past when you used another Deck does not mean it will help with a new Deck. Different cards are good in some Decks and not so good in other Decks.