I think going over the official google guide is a decent start.
https://developers.google.com/search/docs/fundamentals/seo-s...
https://developers.google.com/search/docs/fundamentals/seo-s...
1. Do people find this advice this work for all SEO, or just Google? Are there things Google suggests that are going to harm ranking with other engines? Are there other steps needed to make sure you're ranking well with DDG, Bing and others?
2. If everyone in a similar niche is doing the exact same thing, how do you differentiate? Is it purely about quality of execution? This has always slightly confused me with this aspect of SEO guides...
It‘s the same, for practical purposes. Other search engines have miniscule market share.
Optimizing for OpenAI and Anthropic might be an interesting avenue, though. Has something been published about that?