On maybe one rare, we could create a push-your-luck thing, where the first counter is great, but the second counter is terrible, making you reconsider cards that add 2 or 3 counters at once
Karn is Back And he's better than ever
Balancing how many basic lands of the appropriate types to play alongside our Summits and Catacombs is important since our plan is to curve out and use mana every turnmaking Frank Karsten's article on the math behind them in Standard required Pirate reading materials
(And keep in mind that instants, sorceries, and enchantments that create tokens don't count for this.) If you're going to go tribal, make sure you're taking full advantage of the tribal cards you're working to play
On the other hand, you could just bring back one huge Eldrazi monstrosity, depending on what youre up against