One thing I learnt from the past experience is that we should not slog for the company.
My way of working is to come on time and do your best in the allotted time. Try to do your job right in the beginning it self.
Over time should not be encouraged.
The most enjoyable part in the company is when you finish the Project on time and with good profit.
Tough times in the companies are when the project is coated with less hours and task to finish it.