I'm quite interested in productivity hacks and I've adopted / created a few systems of my own. The key insight in the OP, that you'll eventually do what you truly care about, is one that took me a few years to realize, yet unfortunately it's also a vast simplification.

For me, there are many tasks that I know I enjoy, whose results I know I care about, yet, if left to my own devices, I don't go and do them because the activation energy is too high. I offer two examples: running (I always feel great afterward and I know it's good for me, yet it's a hassle to actually get out there and run) and working on side projects (I love learning and building, yet I don't do it as often because I get mentally blocked by how overhelming a project is before I begin).

Previously, I would make up excuses (I don't have enough time... too busy... much school work... overcommitted) and my personal projects languished as I got caught up in external commitments. The biggest tip in my productivity system is this: Every month/week/day, write down the one thing I most want to accomplish for that time period, that I would likely not accomplish otherwise. If I can accomplish that one thing, I can call that day/week/month a successful one. I track my progress and results as well.

With this one objective system, I found myself delegating time for these projects and implementing all sorts of hacks to reduce the energy barrier of starting these projects.

Another way to think of this is how you structure your priorities. Instead of saying 'I don't have time', try saying 'it's not a priority' [1]. This lets you tell exactly what you do care about, and frequently, that set of things you care about is still larger than the set of things you get done.

[1] http://online.wsj.com/article/SB1000142405297020335870457723...