The scriptures counsel us to avoid “vain repetitions” when we pray. I understand the word “vain” in a manner consistent with its usage in the commandment not to take the name of the Lord in vain. I think this means something like what God condemned as generally true in Christianity: having the form of godliness, but denying the power thereof.
As a practical matter, we typically say this means not to use the same phrases in our prayers in a thoughtless manner. Repetition per se is not condemned, only vain repetition. It seems to me that we should have the same concern regarding our actions as regarding our prayers. It is easy to “go through the motions” of taking the sacrament, for example, without making it meaningful.
But one problem that arises for me, at least, and I suspect for some other people, is that repetition itself can tend to make the repeated activity routine. I suppose this can be a good thing; good habits are better than bad habits, and probably better than no habits at all. But when something is a habit, how do we avoid making it a “vain repetition?” How can we make sure that our (good) habits of scripture study, prayer, Family Home Evening, partaking of the sacrament, temple attendance, and so forth are really meaningful each time, and not vain repetitions?