Hey fellow Planeswalkers! When building a deck in Magic: The Gathering Arena, always consider your mana curve. Make sure you have a good balance of low-cost and high-cost spells to ensure you can play something every turn. Don’t forget to include cards that can deal with different types of threats, like creatures, enchantments, and artifacts. And most importantly, playtest your deck to see how it performs and make adjustments accordingly. Good luck, and may your opening hand always have the perfect mix of lands and spells!