Magnesium threonate. 1 capsule in the morning, one before bed. Result- need one less hour of sleep! 

Chewing nicotine gum while learning new material

Intermittent fasting with an 8-10 hour feeding window, following the same scheduled hours each day.
[even if your schedule is in flux, your fasting/feeding window should remain relatively constant]

Increasing high quality fat and protein intake; reducing sugar, simple carbs, and grains.
[this is not an aim to go into ketosis, no need to be extreme]

Cold water immersion. (Can be as simple as =>1min in shower under cold water)

Drink enough alcohol to achieve ~0.075 BAC before working on tasks requiring creativity / lateral thinking

Eat more complex carbohydrates (chickpea pasta, lentil pasta? - trader joes has some good lentil pasta, and goodles are a decent mac and cheese replacement).  

Supplement to ensure adequate vitamin and mineral levels 

modafinil 50 mg 2-3 times per week (lowish dose; could go lower for less effect)

Answers can be anything that seems to have an end result of increasing my productivity or accuracy at cognitive tasks. For example, if a drug reduces my amount of sleep needed by 30% while leaving my waking behavior unchanged, that counts. I will also allow answers that aren't drugs at all, like exercise or a dvorak keyboard.

It must be an easily noticeable effect. If I have to do some complicated tracking and statistical analysis of my behavior in order to notice the effect, that doesn't count. (I may make an exception if I'm somehow still highly confident that the effect is real and worth the costs; the goal is to avoid borderline cases where a positive effect may just be placebo or measurement/statistical error.)

The overall effect must be positive. Negative health side effects are allowed, as long as the positive outweighs them. Cost is not a factor; if a drug is too expensive for me to regularly take it, I'll still resolve YES if I'm somehow able to test it and it works.

Answers should be specific. Don't submit "a brain-computer interface", submit the name of a specific item that I can purchase. Don't submit "exercise", submit "a half hour of brisk walking every morning". The idea is that I should be able to tell from the answer exactly what I should do, and tell from the probability whether it will work; if I have to do a bunch of extra research about how to implement the answer, that's not helpful.

I'll N/A answers that are not actionable or seem to be trying to exploit the system. (e.g. submitting garbage and betting it to almost 0% just to steal the subsidy.)

Each answer resolves if/when I try the intervention, after I'm confident it does/doesn't work. If I resolve an answer to NO and you think an alternative implementation might work, feel free to submit it as a new answer. (e.g. I try the standard dosage of a drug and resolve it to NO, but you think that a much higher dosage would work and still be safe, you can submit a new answer with the new dosage.)