Here goes for myself, on the tactics that I've tried most seriously:

• Utility Function Experiment; +7; sustained success (short of goal, but much better than status quo) over 6 months.

I've had the best success with the points system I invented after the fashion of taw's Utility Function Experiment. (It differs from the original in that I'm rewarding myself for good results, and trying to meet certain fixed goals as well as trying to maximize on an absolute scale.) It's dramatically improved my productivity over the past six months, and hasn't stopped working yet, though it's required some tweaking. The main side effect is a tendency to subconsciously try and game the system, which makes the tweaks necessary. I should note that a few of my friends were intrigued enough to start their own versions, and have had generally positive results as well.

• LeechBlock; +5; moderate success over 2 months.

It's helped to use LeechBlock to deactivate my preferred timewasting sites when I should be working or sleeping (12:30 AM to 5 PM, Mon-Fri), though I find I need to install it on my secondary browser as well. I've changed my time zone a few times to dodge it, but usually doing so is enough of an inconvenience that I stop wasting my time.

• Applied Picoeconomics; -2; total work ethic collapse for the month I tried it.

Resolutions of this seem to be a feast-or-famine kind of thing. After making a hard-and-fast resolution to do 3 hours of math each weekday for a month, I crashed and burned early and ended up demoralized for the rest of a wasted month. It wasn't much worse than the previous month, but it was worse.

• Melatonin; +3; some success but hard to distinguish from placebo effect.

Intrigued by gwern's article, I gave it a try. It did help me push my sleep schedule back a half hour a day in preparation for a conference that required me to be up at 6; I was tired during the days, but felt less tired than I expected to. For steady-state use, I haven't been able to see as much of a difference as gwern testified to.