Use other front ends. Learn how they work. For example, steepshot.io isn't just a photo site... there's enough space in the "description" space to allow up to about a 300-word post. PLUS you get to use up to 10-12 tags. That's pretty cool!
Engagement, engagement, engagement! Don't just POST things. Get people involved in your posts by finishing them with one or more questions. Comments come more readily when people have a writing prompt.
Stop worrying about the price of Steem, every ten minutes!
If you're a newcomer, look around for contests and challenges. It's a great way for a small account to get an extra boost, and because they attract a lot contestants, it's also a great way to attract new friends and followers.
If you're motivated by friendly competition and want to engage with lots of people, join @abh12345's "Curation and Engagement Leagues." No cost; weekly prizes; lots of good people.
Focus less on "quality" content, and more on whether you are adding "value," in some way... "value" meaning what you post inspires people to interact in some way, rather than just pass by. Are you funny, educational, weird, informative, expert? Don't just spam crap... nobody likes that HERE, any more than on Facebook.
Mostly, just have a good time. As @whatsup said, it's a SOCIAL site. So be social. Don't just "beg for money and upvotes," that's just annoying.
Nice list also!
A few new ones. thank for your input!