Most require you to have both halves in play, like Brisela, but others may require both halves to attack (like Mishra, Claimed by Gix), or have a certain amount of cards in your graveyard (like Titania, Voice of Gaea)
Kamigawa: Neon Dynasty introduced several new card variants at different rarities, making opening many of these special variants exceedingly hard to achieve
Cycling strong creatures like Titanoth Rex or Waker of Waves early in the game makes sure that your commander is always big when it enters, and synergies with ETB effects or +1/+1 counters work great here
The Sheiny fakes use the vertical shine pattern that counterfeits typically have: and this Amoonguss ex card was packed in a White Flare pack, despite being a card from Journey Together
Simple: Ultra Pro always produce high quality Toploaders that are consistent, solid and reasonably priced