Force of Will, Mana Drain, and more recently Force of Negation are the premier efficient ways to counter spells, requiring either no mana from you, or rewarding you with a tidy portion the following turn
Precons are a great on-ramp for starting players, so they modeled the Zendikar Rising precons off the decks from Commander Legends , which were designed much earlier
Simply tap dear old Krenko and you get to add X 1/1 red Goblin creature tokens where X is the number of goblins you control
Many Druids have abilities that ramp mana, untap lands, or fetch additional lands from your deck, making them ideal for strategies focused on accelerating your game plan and casting large spells ahead of the curve
Maintaining detailed records of your cards enables you to easily track what you own, which helps prevent duplicate purchases