Peppy Gals or Universe Survival Saga cards increase the chance of drops. The following characters have both of those categories and double the drop chance.
Saiyan Spirit Super Saiyan 2 Gohan (Youth)
Passion Beyond Pride Super Saiyan 2 Vegeta
Proof of Resurrection Golden Frieza
The Supreme Warrior Super Gogeta
Emperor of Iniquity Frieza (1st Form)