Hardwork means 1) More efforts and 2) More Concentration.
A lawyer in Delhi had a office near Court. His office had 9am Rule. The juniors and clerks who came after 9am, were not allowed to enter. Office doors used to close at 9am for Juniors and clerks.
I also know another advocate in Ahmedabad. He is no more at present. He had 7am Rule. The juniors and clerks in office must be present in his office before 7am.
These are some of the hard work rules which I had seen.
In my beginner days in Supreme Court, I had a 9:30am Rule. I used to be in Bar Library before 9:30am. I followed this Rule for many years. 
Haresh Raichura 30/3/17

If someone asks you, “Would you like a cup of tea?”
You may answer “yes” or “no’ as per your mood at that moment.
But if you say, “It is my principle not to take tea at this time”, then you are showing “Obedience to principles”. That makes you stronger than others.
And if you say, “Generally, it is my principle to not to take tea at this time”, then you are showing “Obedience to principles with flexibility to make exceptions if need be”. 
Summery: Those who show Obedience to principles are usually good and reliable. 
The question of Obedience to principles comes only after we have decided to follow some principles.
Haresh Raichura 26/3/2017