I don't know nearly anything about SEO and haven't used any add-ons to improve it on my site. However, I was pleased to notice that my music forum is listed on the first page of search results for several songs by mainstream artists. Since I obviously haven't done anything to it, haha, I'd say it's apparent that the beneficial search results are because of XenForo's built-in SEO. Hopefully this will help boost activity on the forum in the future as I continue to build content.
Just wanted to say thanks to the XF team and community!