LINCHPINSEO provides an interesting infographic on increasing Twitter engagement. This is targeted to brands, but there are some helpful tips.
The key is understanding that there isn’t a “silver bullet,” nor can you manipulate people to retweet you, etc. Post interesting tweets and you’ll be retweeted. Content is king, the rest are just suggestions.
The primary suggestions that I believe are valid for brands or individuals.
1. Hashtag usage. Using appropriate hashtags help you engage people beyond your followers. Using too many clutters up the tweet though.
2. Shorter tweets. This is just common sense. It is easier for people to retweet you if you give them “space.” to do so. I prefer old-style RTs myself. I also like it when I have enough space to add my own comment.
Twitter Cheat Sheet , an infographic by Linchpin Infographic Design