Ask HN: What SEO advice works for early-stage SaaS?

I’m trying to cold-start SEO for an early-stage product (LaunchSaaS) and running into a wall.

So far I’ve tried:

using Ahrefs + Bing Webmaster Tools to inspect backlinks

submitting to some directory sites

improving on-page SEO copy

writing a few blog posts

But traffic is still basically zero.

For those who’ve successfully gone through this phase: what actually worked for you early on? What turned out to be noise or a waste of time?

Curious how others approached the cold-start phase.