I have been considering in many ways on how people think and conceive ideas, ect. and I think i have one of my own.
It may sound cruel and unnecessary, but that's not what it's about.
To explain, a good example would be;
A friend gets a B on a test.
The second worst thing you can tell your friend at this point is that they did a good job. (The worst of course is giving wrong advice such as "C is better than B", which may not be a good example but it follows the pattern)
A better suggestion is to say "why not an A?"
If they get an A, "why not a 100%"
if they get 100%, then that's to be expected.
This is called speeding up the process of humanity. Raising the bar will benefit mankind. Not just with schoolwork, or whatever, but anything.
It may sound mean, but it works.