We're members in a local store's loyalty program. They sent out an email last week, it was short but it thanked us for supporting them during the pandemic and gave us a small coupon.
Nothing groundbreaking or innovative. Just a reason for the email and a simple loyal customer offer.
You don't have to have a 142 page loyalty system with tiers, double-days, or points (the points don't matter).
You just need to know who are loyal, ideas about what might interest them, and the courage to contact them.
Repeat Customer Insights can help you with the first two, though you're probably an expert on the second even if you don't admit it.
And the third, courage... you can always fake it the first few times. Then you'll realize it's easier than you thought.