An idea for what to do to improve community engagement (this isn't really for steemstem management but for others) will be listed here.

Give tips to users on how to improve their writing on posts from tips to using markdown/html all the way to providing tips to getting content.

Comment, ask questions, create discussions.... But also when writing posts, leave points open for people to ask comments or give little teasers if possible.

Make response posts. So lets say someone writes a post on science proving that jelly belly jelly beans are the best type of jelly bean but you found sources that say other jelly beans are better, or maybe you found evidence that points to it all being personal preference, write an entire post about it in response to theirs. Don't attack their post but realize that this is a type of engagement rarely seen.

Vote on content, either manually or trail the steemstem vote (by either giving your private posting keys to anarchyhasnogods or using a trailing service)

Write about something you are passionate about.... So what I mean is maybe you really like jelly beans, make a steemstem post about jelly beans like "cool science facts" or maybe go with "statistics of jellybeans" and do like a cool math thing surrounding it... Maybe even create a special taxonomical classification flow chart for different jellybean bags and stuff. Like create content you are passionate about that is fun to write, because if its fun to write then it is fun to read. Just make sure to add in references to the science stuff too.

Collaboration posts. Like maybe author A could write part 1 and author B could write part 2, or you do something like @zest and @abigail-dantes where they are each writing on a specific topic from different perspectives (anthropological versus psychological)

And more... The point is, it would be so easy and so much fun to have a community that actively engaged. I can give examples of times that happened even in my experience (before I became a curator) and they were some of the most fun I had ever had while posting. I mean there was this post by trumpman where a guy lit his cat on fire by lighting his fart on fire while a cat jumped through his fart (no idea where it is located now) anyways I responded to it with a post to try and see if it was possible, and someone else responded to mine with a post arguing the otherside... and so on. The point is that we actively engaged and it was fun... So make it fun, become a community, get to know eachother and make inside jokes. You don't have to know everyone in the group, but you should strive to learn something from people, whether they have 10,000+ SP, 1,000+ SP, or less than 20 SP (and that category I missed, ignore them, they suck... Just kidding, get to know them too, they are awesome)

I challenge all the steemstem community members to do something off of this list that they haven't done. If you have never done a colab post, then collaborate with someone... maybe make a series with someone... Idc what, just have fun and get to know others in our group, we have some really amazing people here and we could do some very great things.

EDIT
This doesn't mean all of your posts have to be, like, top notch collaboration posts or that you have to do these things 100%. These are just some ideas on how to promote engagement in the community but there are way way way more ways. I don't want anyone to think that these are guidelines.