Once you’ve found a few keywords that might work, modify your blog post’s title to include it if you can.

Of course the other thing to do when you’re resharing the same piece of content is to mix up the timings of your updates. If you first tweet a piece of content at 9am – at least wait a few hours to reshare it so that others in different parts of the world are likely to be online. The same thing applies to other networks (although I’d wait longer than a few hours to reshare on networks like Facebook or Google+). Also consider avoiding sharing during those times of the day that are particularly ‘noisy’. Sometimes sharing during times that you’d think your audience isn’t online is actually best. Dan Zarrella calls this ‘contra-competitive timing’ and has some great data on the topic here.