The Festival Questbook notes that booster packs are the best way to build your collection since you get twelve new cards in each pack
Another option to crash on Commander games, are the Counter Intelligence deck from Edge of Eternities and the Turtle Power
Lorcana Character cards also will have the card's Strength (damage dealing potential), Willpower (defense or health), Lore value (how much lore it earns when questing)
This is good in two-player matches, but unparalleled in multiplayer games as you literally take your rivals further from victory while boosting yourself forward
You can pay two and return one to the battlefield, or other spells in the 99 that can bring characters back
There aren't a huge number of vehicles in this set, but a three mana 4/3 with Reach is a solid baseline, and when you do have a vehicle they can be even better