Quick answer

Spend resin on the next upgrade that makes your active team work. If your main character cannot ascend, target the required boss material; if a weapon upgrade is blocked, check its material domain. If upgrades are waiting on Mora or character experience, use the corresponding Ley Line. This is a more useful default than farming artifacts before you know what your team needs.

Spend resin on the next upgrade that makes your active team work. If your main character cannot ascend, target the required boss material; if a weapon upgrade is blocked, check its material domain. If upgrades are waiting on Mora or character experience, use the corresponding Ley Line. This is a more useful default than farming artifacts before you know what your team needs.

Resin is used to claim rewards from domains, Ley Lines and boss challenges. Check the cost and available rewards in the current game interface before confirming; not every activity accepts the same resin item.

Find the actual bottleneck

  1. Open the character you use most and inspect the next ascension or talent requirement. Note the missing material rather than farming every possible boss.
  2. Open the weapon enhancement screen for the same character. If a weapon material is the immediate blocker, use the in-game source information and check which day its domain offers it.
  3. If the materials are ready but you lack Mora or experience items, choose the matching Ley Line. If neither is blocking you and your team handles current content, consider artifact domains or another character’s upgrade.
What stops your next upgrade? First place to check
Character ascension material The named boss and its reward requirements.
Weapon or talent material The named domain and its current schedule.
Mora or character experience The corresponding Ley Line reward.
Existing levels and weapon are adequate, but equipment needs improvement An accessible artifact domain; expect random results.

Condensed Resin cannot claim normal or weekly boss blossoms. Keep Original Resin for those bosses and check the current reward prompt before spending. (source)

Save time without confusing costs

The current official update says Condensed Resin is crafted with 60 Original Resin and can claim up to three sets of eligible rewards at once. At a reward interface that normally costs 20 Original Resin, the update also added an option to spend 40 for two sets. Read the current screen before spending: a faster claim still consumes resin, and eligibility depends on the reward.

Older guides may say Condensed Resin costs 40 and gives two sets; that described the earlier version. The game also offers Fragile Resin and a Primogem refill. Save scarce items for when you have a specific need, and check the currency before confirming a refill.

If you are close to the resin cap, use some on an immediate need so natural recovery can continue. Before leaving, note the next missing material and the domain’s available day; that turns the next session into a clear task instead of another guess.

Sources: HoYoverse resin management, Luna I update: Condensed Resin changes, talent material sources.

Sources