I have the same issue, and I solve it by offloading the burden of choice to someone else. My wife is a project manager at a company, while I'm self employed; so I give her the job of scheduling my tasks. It's very refreshing to just open your tasks software, see what you have to work on next, and just do it. No overhead of wondering which task to start with.
Your approach is my favorite. I've had an assistant in the past to do just this kind of thing, but now that I'm doing a startup, I can't afford to do it anymore.
It would be great if there were a matchmaking service that teamed people up to do this for each other. I find that it's a lot easier to schedule someone else's tasks than your own—I'd love to trade task-making responsibility with someone else.
