How do you increase organic traffic?

Before writing anything new, open Search Console and sort your queries by impressions. You'll usually find pages sitting around position 8-20 for things people search a lot. Improving those (sharper title, answer the query properly, add what's missing, point a few internal links at them) is the fastest traffic you'll get, because Google already thinks you're relevant. After that, new content around questions your customers actually ask, and fixing anything technical that stops pages getting indexed. Is it a new site or one that's been around a while? The advice changes a lot depending on that.