-- Time less ;)
-- this question feels like it's missing a word or two. What does time-preference mean?
EDIT: Thanks, Arundelo. So basically, time preference ~= level of short-sighted optimization.
In that case, do some projects that strictly require long-sighted optimization. A deadline is one good tool; Telling others what you're doing (in an unequivocal way, so that the greatest disappointment/irritation/harassment is achieved). Of course these tools are nothing new, the point is to increase the pressure as high as you can stand and reduce the amount of 'slack' time you have to allocate to a minimum.
On a more meta level, you can try things like doing some mindfulness meditation every day, which I personally find makes it easier to ignore irrelevant stimuli, worry less, and stick to my priorities.
An even more general observation: Introverts typically have lower time preference relative to extraverts, so ask them about how they dispel distraction. (I say this in the sense described by Dorothy Rowe: 'extraverts are basically worried about belonging and feel understimulated, introverts are basically worried about keeping control of themselves and feel overstimulated' , and not the vague 'Extraverts are social, introverts are not, derp' that seems to be the misapprehension of the average person)
In case there's any question, I'm an extravert, so yeah, I tend to struggle with this issue too.
Telling others what you're doing
I read somewhere, might have been on lw, that telling what you're doing might decrease your chance of success, because it provides a way to get compliments without actually having achieved anything yet. I suppose this depends on how you do it, though.
Introverts typically have lower time preference relative to extraverts, so ask them about how they dispel distraction.
I'm an introvert, have terrible problems with time-preference, and don't understand the rationalization by Dorothy Rowe you provide.
Any empirical sources for your claim?
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.