You constantly have to build on your profile and provide value to the community. Your reputation is based on the up-votes you receive for posts and comments. I think Steem power may come into play a little bit as well. Just write quality content about things you know..Also, up-vote and comment on posts you think are quality. I've been reinvesting in Steem power whenever I make Steem Dollars. But, be careful because Steem could go down in value.