There are guides but it amounts to "use popular services to link to your website". Post snippets on the bird apps, social media hellscapes, and aggregators like this one. Duplicate your content on the blogging services. Have an RSS feed and submit it to discovery engines and web directories/rings. And send me a link so I can index you.

Stickers are neat too.

Depending on how often you write copy and paste to “elsewhere” is the easy answer.

Substack really wants you to use them as a primary publisher so they don’t make it easy to programmatically put content up. Other platforms have varying levels of ease around this.