Whether it be to do your job, get your schoolwork done, clean your house, work on your creative passion, etc.
Bonus points if you’re someone without reasonable self-control so saying something like “I can only have a cookie after I do this/while I do this” doesn’t work for you and you’re just going to eat the cookie and not do it.
Change your perception of the task, instead of it being a ‘thing that you will be happy to have done’ look at it as a ‘thing that are happy doing’,
for example instead of ‘I will be happy to have learned to play the piano so I should force myself to practice’ think ‘I am happy while practicing the piano’ instead of ‘I have to do the dishes’ think ‘I am cleaning these dishes with perfection, and optimising their placement so that they will dry the quickest’
Basically, don’t do things for the end goal, do it for the action itself, live in the present, not in the future. There’s always enjoyment to get from any chore if you approach it from this mindset.
My partner look at me funny when I put my shirts to dry in ascending color order, and my socks all parrallel, but the truth is, I’m having fun doing it that way, the chore has become a meticulous game that I take pleasure from.