I only use Instagram personally, not professionally. I feel like it is too easy to get bogged down on Instagram with things in my feed that irrelevant to my interests (even more so with the new changes that were made to the algorithm). So I try to keep it as simple on there as possible.
Mostly I follow my kids and their friends, as well as those people that are connected through Facebook.
Because I dream of traveling more and love nature photography, I follow several national park accounts like nationalparkgeek, pnwonderland, national_park.usa and explore.the.usa. I also follow National Geographic Travel and National Geographic One Shot.
If I use Instagram in my library (and I probably will), I will create a separate Instagram account that will be reserved for sharing book recommendations and library news.