So how to apply it in practical terms?
Well, you need to figure what activities you think raise your quality of life above 60 per hour, how many points above they go and shave off part of them, putting those points/time in store towards paying off doing personal projects or homework.
And realise that your actual quality of life is, if you wish to have some control over what you do in life, lower than you thought it was. Every bit shaved off lowers your average quality of life. And that's hard to face!
However, shaving off just a part can feel like it's just a part - and you are doing enjoyable things, in part, towards racking up more payed off homework/project time. Probably shaving off 10 points/ten minutes from the activity towards paying off homeworks potential 30 quality of life per hour.
Write those stored times down. And when you use, them, cross them off.
You can see how this reverses the traditional 'stop doing fun things, that's how you get homework done' ideology.
Your instinct is to enjoy a certain quality of life, not lower your quality of life for a decade(s) distant goal. The old ideology doesn't cut it.