This is solid advice. I'd add that community presence matters more than you might think—but it has to be genuine. Hanging out in Slack groups and actually helping people (without immediately pitching) builds real relationships. When you do mention you're consulting, people already know your work quality.
The portfolio/OSS combo is key because it removes risk. Clients can see what you actually ship, not just what you claim. Even small open source contributions help more than you'd expect.
One thing missing: referrals. Your first few clients are the hardest. But if you do good work, they'll refer others. That becomes your growth engine pretty quickly, so don't treat early clients as one-offs.
RiteTag offers the world's first real-time hashtag grading system which aids users in modifying their hashtags to nail the ones most likely to get their tweets discovered by topic-opted-in audiences.
Browser extensions provide this goodness within Twitter for free users and for paying users, also in Hootsuite, Tweetdeck, Buffer, SocialOomph, and SproutSocial.
Yes, and many people set up a column in Hotsuite/Tweetdeck/etc. to track a few hashtags passively. When someone's using #ritetag or #startuplife, #hashtagmarketing, I see it this way.
There is personal experience - from our people and the many that talk about hashtag successes. As examples, "operation wallstreet" rallied tremendous community support with #ows and then related hashtags like #owsboston etc. When there was media blackout about a rigged election in Iran and phonelines were even blocked, a hashtag spread the truth. What's more, it was my personal experience, during the big earthquake and tsunami (tidal wave) in Japan, and seeing how I could find very relevant tweets from hashtag streams rather than the cover-up on Fukushima on TV that led me to understand that hashtags have power - but that no one knew which was any better than another.