Bole is obviously meant for your main tank, though it has some niche use protecting weakened characters from party-wide attacks. Expanding this effect dilutes it considerably; a 5% reduction is very small, though when stacked with Collective Unconscious or Sacred Soil it’s noticeable. Extending the effect on a tank is fabulous for large trash pulls or boss fights, and Enhancing the effect gives you breathing room if needed. It is better to burn a Bole than a Balance if you want to Enhance your next card.
If you are able to Spread a Balance card and burn an Ewer or Spire, you can start a boss fight with a group-wide damage increase of 5%, on top of the opening burst all jobs are capable of. Balance is generally not a good candidate for Expansion mid battle in 4 man content otherwise; that is better spent on Arrow. Balance is best spent on your strongest DPS. If you are in a group you know, use your knowledge of the players to apply this card. Extending this card is always good, and Enhancing it also a valid option. In 8 man content, however, Expanding Balance is an excellent use of your cards; any chance you have to do this, go for it. The only time you should ever burn this card for Royal Road is during a lull when Spread is unavailable.
If you have melee DPS in your party, they will love getting Spire during extended boss fights or large trash pulls. If you don’t, the tank is always a good recipient of this card. Expanding Spire dilutes its effect, but no melee or tank is going to say no to free TP. Extending and Enhancing this card are powerful options, but should not be your first choice. At the beginning of a fight, or after a lull, is the best time to burn this card for an Expanded effect. You can see your party’s TP bars; use those to gauge where Spire should go. It will fill up 10% of the bar, so if it’s more than a quarter empty, you won’t be wasting the card. Spire is a card that is probably better burned more often than not, as most Heavensward boss fights have lengthy lulls where TP regenerates on its own.
Arrow is another extremely powerful DPS card. Lowering a MNK or NIN’s GCD even further ramps up their damage considerably. BLMs, who do not worry about resource management, also love this card. DRG, SMN, BRD, and MCH all benefit as well, but their damage is more drawn from DOTs and Abilities, neither of which are affected by Arrow. Extending this card can be detrimental to a melee’s TP management, but a BLM will love it. Enhancing this card is never a bad idea. Expanding this card is excellent at the start of a fight. I do not recommend ever burning this card during battle, the increased attack speed is far too valuable. Unless you’re in a lull, of course.
Ewer is best used on healers, bar none. BLMs do not need mana refresh, and SMNs do not struggle with mana any longer. If you and your cohealer are doing well on mana, or it’s the beginning of a fight, you can use this on a Paladin or burn it for an Expanded effect. Dark Knights cannot gain this card’s effects while Darkside is active. This card isn’t wasted if you play it on a SMN or BLM, but it does little to impact their effectiveness.
Spear is a strange card. It is potentially gamechanging, but requires extremely precise timing that is unlikely in a typical duty finder PUG situation. Spear can reduce the cooldown of Hallowed Ground by over a minute, or Benediction by exactly a minute. But it must be in place before those abilities are used. For this reason, it’s very difficult to apply effectively without very good communication or familiarity. Spear is often best used on yourself, to speed up Essential Dignity, Celestial Opposition, Luminiferous Aether, and Swiftcast, or burned to provide your next card with Extension. However, Bards, Summoners, and Machinists all use abilities as part of their core rotation enough that you can safely hit them with a Spear and see gains from it; reducing Reload, Deathflare, and Bloodletter cooldowns will make their lives better!
Please note that, while I make these recommendations based on my experience with the job and my experience raiding in general, your judgment is always the most important thing! If a MNK has just raised and you have an Extended buff and Draw Spire, lay that card on the MNK to help with TP management! If you’re on TeamSpeak with a Paladin and she tells you she’s about to need Sentinel, get Spear on her ASAP. The fun of the cards is how often you’re able to apply them, and the flexibility and liveliness they add to your healing duties.