You need to do some keyword research. What are people interested in this niche searching for?
Then you create content around that keyword. This is usually in the form of a blog post. It needs to be good content, with content breaks like pics, lists, infographics, etc. this is more important the harder the keyword is to rank. You can also invest in link building to help give you an edge again, in those difficult keywords. But it’s a minefield, check my pinned posts I’ve got some good info on link building there.
If you’ve already done all of this then look at your interlinking, that’s vital. How is your content velocity? What’s are you competitors doing that your not? You’re websites will be all about informational content so I’d focus on your content and make it stellar and support it with some link building efforts depending on where you currently rank.