Hey fellow Planeswalkers! When building a deck in Magic: The Gathering Arena, always remember to have a good balance of cards. Include a mix of creatures, spells, and support cards to ensure versatility in different game situations. Don’t forget to keep your mana curve in check to have a smooth flow of casting spells throughout the game. And most importantly, playtest your deck regularly to fine-tune it based on your gameplay experiences. Good luck and may your opening hand always have the perfect mix of lands and spells!