Instagram is a major platform for advertising in 2019. If you want to maximize your reach, you need to know how the algorithm works.
The Instagram app has an algorithm just like Google, and theirs also focuses on quality and personalization. Einstein Marketer said, "This Instagram algorithm ranking factor puts a heavy emphasis on business accounts publishing high-quality content, every single time they time post."
You should be posting the right amount of quality content as well. You don't want to post too much, but you definitely don't want to fall behind. 1-3 Instagram posts a day seems to be the sweet spot.
Finally, post stories! They are a great way to interact with your followers on a more casual basis.