OP there are plenty of ways to make your mind work much better - meditation and brain games (lumosity) are two of them.
But if you want to cut to the chase and get large quantities of work done without blinking Modafinil is the legit.
This is only a personal recommendation, you might try it and hate it, but I don't know anyone that has tried it that didn't rate it more than any other cognitive enhancer.
It can make you a bit anxious if you take a lot, you don't need much. I take 1/4 of a tablet to last all day. I've written 10,000 words of content in one day on Modafinil and smashed university coursework that I would have failed otherwise.
I know it sounds a bit like a promo, but I'm sure someone else that has a much higher rep than me whose taken Mod will say the same thing. DYOR