Hey there! When it comes to deck-building in Magic: The Gathering Arena, one of the key things to keep in mind is having a good mana curve. Make sure you have a good balance of low-cost, mid-cost, and high-cost cards to ensure you have plays at every stage of the game.

Additionally, consider the synergy between your cards. Look for cards that work well together and support your overall strategy. Don’t just throw powerful cards into a deck without thinking about how they fit with the rest of your cards.

Lastly, don’t be afraid to experiment and make changes to your deck. It’s all part of the fun of deck-building! Try out different combinations, see what works best for your playstyle, and don’t be discouraged by losses. Keep tweaking and improving your deck until you find the right balance. Good luck!