This is upper-intermediate grammar, and quite easy to look up. Here are a couple of helpful sites: http://www.oxfordlearnersdictionaries.com/definition/english/try_1 http://www.engvid.com/try-to-do-try-doing/ (I hope you can see this video) The other verbs to be careful of are "remember" and "stop". The meaning changes depending on the verb-form that follows.

Basically, "try to do" is something in which you are making a personal attempt. As where, "try doing" is more of a suggestion based on what someone else has suggested. In a way, try doing would be closer to performing an experiment.