Hey fellow Planeswalkers! When it comes to deck-building in Magic: The Gathering Arena, remember to focus on synergy between your cards. Choose a theme or strategy for your deck, whether it’s aggro, control, or combo, and select cards that support that strategy. Don’t forget to have a good mix of creature spells, removal, and support cards to handle any situation. And always playtest your deck to fine-tune it. Good luck out there on the battlefield!