This is a trick that I use for getting out of bed in the morning - quite literally: I count down from 10 and get out of bed after the "1".
It works because instead of deciding to get out of bed, I just have to decide to implement the plan to count down from 10 and then get out of bed. Once the plan is in motion, the final action no longer requires an effortful decision - that's the theory, anyway. And to start the plan doesn't require as much effort because I just have to think "10, 9..."
As usual with such things, there's no way to tell whether it works because it's based on any sort of realistic insight or if it works because I believe it works; and in fact this is one of those cases that blurs the boundary between the two.
The technique was originally inspired by reading some neurologist suggesting that what we have is not "free will" so much as "free won't": that is, frontal reflection is mainly good for suppressing the default mode of action, more than originating new actions.
Pondering that for a bit inspired the idea that - if the brain carries out certain plans by default - it might conserve willpower to first visualize a sequence of actions and try to 'mark' it as the default plan, and then lift the attention-of-decision that agonizes whether or not to do it, thus allowing that default to happen.
For the record, I can remember a time some years ago when I would have been all enthusiastic about this sort of thing, believing that I had discovered this incredible new technique that might revolutionize my whole daily life. Today, while I know that there are discoverables with that kind of power, I also know that it usually requires beginning from firmer foundations - reports of controlled experiments, a standard theory in the field, and maybe even math. On the scale of depth I now use, this sort of trick ranks as pretty shallow - and in fact I really do use it just for getting out of bed.
I offer this trick as an example of practical advice not backed by deep theories, of the sort that you can find on a hundred other productivity blogs. At best it may work for some of you some of the time. Consider yourself warned about the enthusiasm thing.