Email feels like something you earn after you already have an audience, which is exactly backwards. The best time to start collecting emails is before you have a following, because your very first customers are the easiest people to convert into a list — they already bought something, which means they already trust you more than a stranger scrolling past an ad.
The simplest starting point is a post-purchase incentive: a small discount code (5-10% off a future order) offered in exchange for signing up, either at checkout or in your order confirmation email if your platform supports it. This converts customers who already like you enough to buy once into people you can reach again without paying for another ad or hoping they stumble back onto your store.
If you're on Etsy specifically, you're limited in how directly you can push people off-platform for marketing purposes, so a packing insert with a QR code linking to a simple sign-up page (even a free Google Form or Mailchimp landing page) tends to work better than trying to embed sign-up prompts directly in listings.
Once you have even a small list — 20, 50, 100 people — the actual sending doesn't need to be complicated. A short monthly email showing new designs, a seasonal collection, or a limited restock is enough to keep a small list warm. You're not running a content marketing operation; you're just reminding people you exist right before they'd otherwise forget.
The mistake to avoid is over-emailing a tiny list and burning it out before it's even grown — for a small store, monthly or even every-six-weeks is plenty. The goal in year one isn't sophisticated email marketing, it's just building the habit and the list itself, so that by the time you do have real volume, you're not starting from zero.
Free tools like Mailchimp or MailerLite both offer functional free tiers well past what a small store needs starting out, so there's no real cost barrier to beginning this on day one rather than waiting until you feel like you've "earned" an email list.