@shenanigator has compiled a great Steemit FAQ with the support of the community :) It has a good overview on all the factors that go into raising one's reputation.

Excerpt from part 1:
How do I improve my reputation score? What hurts my score?

To put it simply, add value to the Steemit community to improve your score. But harm the community and your score will suffer.

Create and post quality original content. It’s all about quality, not quantity.
Engage in thoughtful discussions in the comments of blog posts.
Up-vote thoughtfully. Don’t upvote junk, only vote up quality content.
Build your following by posting quality content.
Avoid bad behavior; it can get you flagged.
Don’t harass other users or become disrespectful due to an online disagreement. This can lead to trolling habits which could get flagged.

Steemit FAQ
Part 1: https://steemit.com/steemit/@shenanigator/thanks-to-your-help-the-official-steemit-faq-is-now-complete
Part 2: https://steemit.com/steemit/@shenanigator/thanks-to-your-help-the-official-steemit-faq-is-now-complete-part-2