Once you’ve picked your deck theme and colors, you’re ready to put your Magic deck together! Your deck will contain land, creatures, enchantments, artifacts, instant and/or sorcery spells. A good starting point is to gather up all the Magic cards you think would be good candidates for your deck, and narrow it down to 60 cards as you focus your theme.
Land: Depending on the mana cost of the cards in your deck, and the number of colors you’re playing, you will probably be best with about 22 to 24 land in your deck. A fast mono-green deck full of cheap creatures may only need 18 to 20 land. In contrast, a two-color mana-heavy control deck might need 26 to 28 land. The best way to figure out how many land are good for your deck is constant playtesting.
Creatures: Find a good mix of creatures that fit with your deck’s theme. Pick creatures with a good relative power to casting cost ratio. Evasion and “come into play” effects are extremely handy.
Enchantments: There are two types of enchantments, global and local. Local enchantments are played on a specific card, such as a creature enchantment. When the creature dies you lose the enchantment. Global enchantments, on the other hand, are not played on a specific card and work by themselves. A few good enchantments can help your deck when played at the right time.
Artifacts: If there are any artifacts that help your deck, make sure to include them. If your deck is based on creatures, you may benefit from equipment artifacts. Equipment is often better than creature enchantments as it isn’t destroyed when the equipped creature dies.
Instant and Sorcery Spells: This includes removal spells, counter-magic, and any other non-permanent spells. Instants are preferable because they can be used anytime (even during your opponent’s turn!) but sorcery cards can be helpful too. Make sure to include a good variety of spells to handle opposing threats.
How Many Copies? You can have up to 4 of any card (except basic land) in your deck, so how do you choose the right amount? Any card with a low casting cost that’s critical to your deck should contain 4 copies. A good example of this would be Lightning Bolt or Mana Leak. You might only use 1-3 copies of cards with higher casting cost, or cards where only one is needed at a time. For example, you want to have formidable creatures in your deck, but you don’t want several of them in your opening hand.