Don’t just retweet and quote people. Directly respond to them with @mentions.
Sometimes you can retweet and respond all in the same tweet. <<Like this.
Don’t set up an automated direct message. Manually message new followers.
Reply to every single @mention you ever get as long as you live, even if it’s just to say thank you. Especially if it’s just to say thank you.
Thank everyone who clicks that retweet button for one of your tweets. Direct message them.
Talk to people about stuff un-Twitter-related. Build bridges between the offline and the online world (it makes you seem more real).
Direct message everyone who lists you. Say thanks.
Ask people questions individually, like through an @mention, not just a blanket blast.
Follow people on #followfriday and then tell them how you found them (tell them who made the connection).
Search for interesting topics through the sweet search box or search.twitter. Engage with people who are tweeting about the topics you’re interested in, particularly people you don’t know.
Use #hashtags usefully. Participate in a community. Add to it. Don’t just use that pound sign as a highlighter.
If you’re following a lot of people, which I suggest, make a list with less than 50 people on it. Call it “twittercore” or “dunbarcircle.” Talk to everyone on the list all the time. If you can’t keep up, make the list smaller. (This is how to go deep on Twitter.)
Use real names whenever you can, especially when messaging people so they know it’s not some fake, automated drone.
Don’t follow Twitter rules all the time. Follow people, and care about them.