Fast mana from Sol Ring, Ancient Tomb, Skirk Prospector, and Jeska's Will help you to cast key pieces early, while Lightning Greaves, Swiftfoot Boots, and Thousand-Year Elixir make sure that Krenko can tap right away and survive removal
These effects are particularly popular in decks with many small creatures, like Edric, Spymaster of Trest, Anowon, the Ruin Thief, and Tetsuko Umezawa, Fugitive
Apart from Tragic Arrogance, the other risky part about playing these cards right now is that a lot of the big decks in Standard are running four copies of Dromoka's Command, which can lead to some huge blowouts
You can substitute Primal Vigor or Doubling Season for Parallel Lives, though the former will affect everyone so you might end up helping your opponents more than you'd like
There are many strategies that can not only benefit from good draws, but more cards being present in one's hand or on one's side of the field
Azusa, Lost but Seeking Playing an additional land each turn is nice, but what about two