I think the most important thing is to do fully whatever you are doing at the moment. Catch those thoughts that distract you and simply continue with what’s actually there in front of you.
100 hours of practice in that concentrated zone will probably get you as far as 1000 hours in a zone where there’s an element of stress. I would say, just stay in the moment, and when you need to think and plan, then take a separate moment for that. And don’t let social stress take you out, social events also happen within the moment 
It will reduce both the pleasure impulse and the counter/guilt impulse that you need to work hard.
So that, and taking regular moments of reflection. Be self-directed, develop your own vision on your work, and keep setting goals and improving your work. An ultimate purpose is not there to be found, the purpose is in the doing itself.
And of course, enjoy it! When there’s no enjoyment, there’s just no real point to it and you may as well stop with what you’re doing.