Hey fellow Planeswalker! When building your deck in Magic: The Gathering Arena, focus on synergy between your cards. Choose cards that work well together to create powerful combos. Also, make sure to have a good balance of creatures, spells, and lands to ensure you can play your cards consistently. Don’t forget to pay attention to your mana curve to make sure you have the right amount of early game plays and late-game finishers. Keep practicing and experimenting with different cards to find a strategy that works best for your playstyle!