My manager tells us not to work on weekends/overtime. (Once in a blue moon exceptions are there)
And he makes sure we get paid for overtime if its a requirement from upper management.
Over the years what I have learnt is that,
First, We should never work overtime in the initial days, it creates an impression that if there's more work, this guy will be there to handle the load.
Second, is the art of saying no.
Third, make sure ur work is noticed. Speak about it, with clarity, let everybody know what you're working on (tip can make it seem like a big thing even if its not).
Fourth, Always show you're busy.
Fifth, after office hours don't think about work stuff, leave it for the next day.
Mental peace is above all.
Work smart not more.