Far too often player do general drills, the type that are great for developing a foundation to their game, but not so great at fixing up specific problems in their own games. To use a completely nonsensical example, suppose you were horrible at spelling words that start with "Q." Would you practice for this by working on all of your spelling, or by practicing your spelling of "Q" words?
Here's a table tennis example. Suppose you have trouble with slow, spinny loops. Perhaps you consistently block them off the end, or too high, or counterloop or smash them erratically. Suppose these slow, spinny loops are mostly against backspin balls. Would you then go out and practice your blocking against someone who loops over and over while you block? No, you'd need to practice against slow, spinny loops against backspin. These are two very different types of blocks.
Instead, design a specific drill to turn the weakness into a strength. If you have trouble with slow, spinny loops, perhaps have your coach or practice partner serve backspin, you push, he loops slow and spinny, and you get to practice against the shot that specifically gives you trouble. Better still, get a box of balls, and have him serve and loop, but don't play out the point - you practice against his slow, spinny loop as he's reaching for the next ball to serve and loop with. You get almost rapid-fire practice against exactly what you need work against, slow, spinny loops, and your partner gets lots of practice slow looping against backspin.
You can apply this type of thing to any part of your game, where you aim to get lots and lots of practice against whatever it is that specifically gives you trouble. Go to it!