Hey, fellow Planeswalkers! When building a deck in Magic: The Gathering Arena, always start with a clear strategy in mind. Focus on a specific win condition and choose cards that support that goal. Remember to keep your deck balanced with a good mix of creatures, spells, and lands. Test your deck against different matchups to fine-tune it. And most importantly, have fun experimenting with new cards and strategies! May your opening hand always be full of land and spells!