Left Foot Strategy
A consistently good move when you don’t have a better clear choice is to aim for an opponent’s left foot. If your opponents haven’t left a space wide open, aren’t both back at the baseline, or aren’t otherwise out of position, one of the best things you can do is drop that ball directly at a left foot. It might be considered more of a defensive move than offensive, although sometimes they won’t be able to return it. In most cases, they’ll return it badly, so you might think of it as a two-part strategy. The first shot is aimed at someone’s foot. That someone will return it badly, and you can then put it away.
Whether your opponent is at the non-volley line, or the baseline, the concept is the same – send the ball directly to that person’s left foot.
Of course this assumes your opponent is one of the 89% of players who are right-handed.
Ideally, you’ll take a moment before the rally to notice whether your opponents are right-handed, left-handed, or ambidextrous, and if your opponent is left-handed, you aim to the right foot. But if you don’t remember or didn’t check, a ball placed to the player’s strong side, as long as it goes to a foot, will generally work well anyway.