Blocking opponents
When you can disable an opponent's card, target ones with the most arrows pointing to the most spaces. This will prevent your opponent from using that card as well as block combos from those directions unless they revive or remove that card. For example, when your opponent starts a combo, neutralize up the card they will most likely to use as the final one in that chain.
Neutral cards
Neutral cards are very versatile. Although they do not have many effects and cannot do damage or heal directly, they are useful to connect other cards. They usually have more arrows than other types of cards, and point in a variety of directions.