Its important to become familiar with your cards, obtain the necessary ones for your deck, practice regularly, and seek guidance from more seasoned players.
All Hallow's Eve Let's start off with Halloween's namesake card, All Hallow's Eve
Loosely packed cards - real booster packs are sealed tight around the cards, with almost no room for movement
Its worse as a 2/1 without an ETB, but once you get your +1/+1 counter engine going, you can recur a big chunk of your graveyard
Few cards illustrate risk-versus-reward (or raw explosive potential) better in the history of the game
Yawgmoths Will + Underworld Breach Though they have different uses, Yawgmoth's Will and Underworld Breach both fuel graveyard-based combos that end the game