I'll first go over how each preconstructed deck plays, why you should buy it, and the various directions that you can upgrade the deck and make it your own
The chosen from the dead
Creatures (25) 4 Anafenza, the Foremost 2 Warden of the First Tree 4 Den Protector 4 Deathmist Raptor 2 Nissa, Vastwood Seer 2 Ayli, Eternal Pilgrim 4 Sylvan Advocate 3 Matter Reshaper Lands (25) Spells (10) Deathmist Raptor, where have you been hiding
Drafting Drafting is arguably the best way to earn the cards you need from a set, but this is only applicable for sets that are actively in the draft rotation
Cosima Landfall deck list The full deck list comes in at $373 and, of that amount, a good chunk is concentrated on Mana Drain, Rhystic Study, Crucible of Worlds and Snow-covered Islands
It goes well with Akroan Hoplite WR Creature Human Soldier (Whenever Akroan Hoplite attacks, it gets +X/+0 until end of turn, where X is the number of attacking creatures you control.) from Theros