My biggest advice right now is to find an extension to block things like Twitter Trends, Topics to Follow, and the like. The ads are a bit harder to work with, but blocking the others will make it easier to shape your experience. A lot of Twitter Trends do deal with politics, news from your region, random hit tweets, and other trending things you may or may not be interested in. I currently use the following link for Google Chrome (I don't know if there are extensions for other browsers, but there should be):
After that, think about following the webcomic sites you're posting to. Webtoon Canvas and Tapas Tapastry are currently on both Twitter and Instagram.I use both as a way to not only promote my work, but also promote the work of others, keep up to date with events, and see if they have any activities going on.
Also follow artists you've been keeping up with -- take note on what they post and how they interact with their audience. You don't have to mimic them exactly, but understanding their process can add more to your own.
I also find that a lot of people enjoy WIPs. Posing process gifs, sketches, and the like, along with questions or your thought process, can really get people engaged with your work.
Another good thing to do is use hashtags. But use them related to your brand, along with broader ones. You want to not only target a wider audience, but also the people you're targeting with your story.
Example hashtags can be:
ArtistsonTwitter
Webcomics
[Whichever genre your comic is: Horror, Comedy, etc]
{The niches/tropes within your comic: Monsters, Demons, Isekai, Princesses, Robots, etc.]
Webtoon and Tapas also have their own hashtags they use, which can make it easier for staff to see your work.
Even more -- engage with other people's works. Like likes, retweets and comments and even think about promoting the comics you enjoy. The biggest help you can do for your own work is promoting others and showing audiences that these things ARE popular. That people DO like them.