As an example, if your game involves medieval knights or warfare, you could choose a wood or leather-looking design for the back of your card to suit the theme
Kamigawa: Neon Dynasty Set Boosters contain: At least 1 rare or mythic rare card (approximately 27% of Set Boosters contain 2 rares or mythic rares, 3% contain 3, and less than 1% contain 4.) 1 Traditional foil card of any rarity, including Booster Fun cards 1 Common or uncommon with the Ninja or Samurai treatment 1 Land or foil land, including ukiyo-e lands 1 Art card or foil-stamped art card 1 Double-faced common or uncommon 3 Common cards that are connected thematically 2 Uncommon cards that are connected thematically 2 Wildcards of any rarity, including double-faced cards, ukiyo-e lands, and Booster Fun cards 1 Token, ad, or helper card, or a card from The List Set Boosters are available individually and in displays of 30 packs
There are also key synergies tokens, and my favourite, artifact aristocrats, getting the most out of cards like Skullclamp or Ichor Wellspring
Then, on the next combat that doubled power is doubled again, and continues to double to exponential power
