Set collecting is the classic approach — you're building a complete set of every card in a specific product release. Every base card, every number on the checklist, no gaps. It's the original way people collected cards, and it's still one of the most satisfying.
Set collectors are methodical. They track what they have, identify what they need, and hunt down the missing pieces through trades, purchases, and pack ripping. The endgame is a binder or box with every single card from the set, organized and complete.
Some collectors go even further and chase "master sets" — meaning they want every base card plus every parallel, insert, and short print in the entire product. That's a serious commitment, but the payoff is a collection that represents the complete vision of the product.