An odd technique, which I'll rate at +5: whilst already locked into some mundane but necessary task (e.g. grocery shopping, dishes, wading through work e-mails), consciously forcing my brain to complete the "Man, I wish I could be doing [blank] instead" template with some other mundane task that I would normally procrastinate - then immediately switching to that other task when the first task is done.

For example: "These dishes are taking so long - I really wish I could be... [hijack the train of thought by picking something else on my to-do list]... doing research for that article." I'll then make my brain, while still doing dishes, concretely imagine working on the article - what I'll search for online, in what order I'll attack the sections, even how I'll format it, etc. - in the ordinary way I would normally fantasize about playing a game, watching a TV show, or some other fun task naturally preferable to doing dishes.

By the time the dishes are done, I literally can't wait to jump into the article. After all, these dishes have been keeping me from it for so long!

I have had a shocking amount of personal success with this.