Now you want to use cards like Urza's Bauble to adjust ratios and have as filler cards but back in the day you could afford these slower but more luxurious offerings
Using spring as an inspiration, the six cards in the first Hatsune Miku expansion pack will all have a sakura, or cherry blossom, theme, called Secret Lair x Hatsune Miku: Sakura Superstar
Invasion of Kylem Invasion of Kylem Battle Siege (As a Siege enters, choose an opponent to protect it
Obvious Upgrades There are some clear upgrades like Priest of Titania or Llanowar Elves in place of Wose Pathfinder which wont change the identity of the deck and are simply smart includes
Preordain Obviously, all the cards on this list have the benefit of triggering all your "Instants and Sorceries matter" cards
Any of your mana-producing Elves can double up now, while your attacking Elves get stronger and gain a functional type of vigilance