Excellent suggestions.

Next to Steemit, my favorite platform.  Can't overemphasize the importance of hashtags.  Unlike Steemit, you're not limited to five tags, although excessive use can lead to hashtag fatigue, where your main focus gets lost.

Also, engage about stuff that genuinely interests you.  You can always include promotional material, in other tweets.   However, I think you build and keep a following by engaging with people who share your interests. 

Anyway, that's my experience.