Imaginary wall helps with lobs
Does hitting the lob give you problems? Do you tend to hit it long one time and short the next? It will probably help if you imagine there's a 10-foot wall on the court.
The lob is often the best weapon you have when an opponent is up at the net and you're back at the baseline. A lob that loops over him can drive him away from the net and maybe even win the point for you.
Many tennis players, though, have trouble getting their lobs high enough and deep enough. If that's your problem, imagine that there's a wall running across the middle of your opponent's court, about 10 feet high . . . or about as high as the tip of his racket would be if he jumped for the ball at his service line.
Now hit your lobs high enough and deep enough to clear that imaginary wall.
They will land near the baseline, but won't fly long. You'll have a new weapon in your arsenal.