Just write your posts and share them in the appropriate public channels on Steemit.chat. Don't send someone a private message to ask for a follow or upvote, because people will avoid you instead.
And with your comments: Try to add value by talking about whatever the post was about. Show appreciation for the authors, without asking them to follow and upvote you. If they enjoy your content or if they enjoy talking to you, they will upvote or follow you.