If you aren't watching your stream constantly, there is no way to catch everytime someone ReTweets you or mentions your name. There is probably a lot you are missing out on. How can you be sure to not let these valuable interactions slip by unnoticed? The answer is simple and will help you become a much better Twitter user.
Step 1. Go to www.search.twitter.com . This great tool will allow you to search for people who are talking about what you are interested in, which in this case is your handle.
Step 2. Search for your term. When I search for "axiompr" (my handle is @axiompr) the search will bring up all the times "axiompr" has been Tweeted. This will find not only my own Tweets, but those times when someone else ReTweeted me or used my handle in the middle of their Tweet.
Step 3. Click "Feed This Query" at the top right of the page.