Grateful offerings are used to purchase cosmetic rewards from your Covenant's Renown Vendor by World of Warcraft Shadowlands, and there is only one way to grow them. Well, more than six ways if we want to cut hair, but they are all tied to a single system that will take time, Anima and Redeemed Souls to fully unlock.
Grateful Offerings in Shadowlands are earned by completing Anima Leader activities.
Grateful Offerings are tied to the various activities you can power up at your Covenant's Anima Conductor, and if you want to collect as many as you can to buy all the cosmetics available from the Renown Vendor, you'll need to stay on top of your Animal Farm. Traded Souls will be fairly easy to earn through the weekly quest, but they will act as a time gate for upgrading your leader anima. You will need at least 1000 Anima and 1 Redeemed Soul to unlock the Conductor first and start farming Grateful Offerings, but you should easily clear this soon after reaching level 60.
Once you unlock the Anima Conductor, you will have access to two activities and you can only activate one per day. You can technically access both if you log in daily, since activity rewards reset with the daily reset, but activity lasts for 24 hours from activation. A double deduction like this means you'll earn more grateful offers per day, starting at 3 per activity. It's the difference between 90 Grateful Offerings per month and 180. Since Shadowlands' most expensive cosmetics require 50 Grateful Offerings and are locked behind rather high Fame Ranks, casual players can easily acquire the amount they need if they follow their Level 1 Anima Conductor.
To make your grateful offerings easier and faster, you'll want to bank your Anima and redeemed souls each week and spend them on Anima Conductor upgrades, which will each unlock two additional activities (up to six total). Also, be sure to activate a new activity each time you log in, because after ten hours you can βreinforceβ an activity to maintain it permanently. Keep it up to finally have six activities each day and more thankful offers than you can spend in Shadowlands.