Optimize your environment for decreased time-preference when you have the most control:

Fill your refrigerator when you're not hungry. Apply effortful-to-dismantle restrictions on your computer when you're not bored and tired. Walk to the university library to study so it takes effort to come back home to your hobbies.

I'd like to read and collect other similar strategies for my toolbox.

ETA: I just realized I do this for exercise too. There's a lake near my house with a circumference of about 6 kilometers, and I go jogging around it frequently. I have a strong desire to quit once I've gotten to the other side, but I have no choice but to run the whole route at that point. Sometimes I decide to walk the other half, but I guess it's better than nothing. Another option would be to just run in one direction and then back, but I find the idea too boring, even if I change my route a bit.