One of my favorite "stacks", back in 2004-5, was to take a 1/2 teaspoon and pour the following on my tongue, chased with a swig of orange juice before going to work:
oxiracetam
centrophenoxine
bacopa monnieri
rhodiola rosea
ALCAR
Along with a couple caps of ashwagandha.
This would be on an empty stomach in the morning. On my commute in, I'd sip on a bottle of Mt. Dew Code Red. Man, I'd feel a little euphoric by the time I got in, and I'd have focus and enthusiastic energy for at least a solid 3 hours.
I'm not sure how that impacted immediate cognition, as this was after I decided I was done with school, but it was around this time that I began to have success memorizing certain things. At the time, I got myself to memorize my check card number, expiration and security code, as well as the numbers of a few local pizza places (before online ordering became vogue).
Nothing has made me more razor-sharp focused than adderall, but that's not practical. However, when I briefly used that, it was more of a short-term memory prep, as it was only used on the day of mid-terms or finals.
DS Craze, with which I have been recently acquainted, has really enabled me with a focused, can-do mindset. After I do my morning exercise, it's still working up to 4-5 hours later, and I'm keeping myself on task. I'm willing to bet that if I had something like Craze back in '98-00, I'd have actually gotten a degree.
As far as chillin' / relaxin', I am of no help. Anything I take to increase brainpower, focus, or memory, just makes me either quiet, "squinty" (like the term Booth calls the lab people on the show, 'Bones'), or maybe a little bit happy or too enthusiastic. This is great for the job, where people rely on me to come through, but in the social realm, it's of no value. I don't suddenly become a brilliant orator like all the fictional kids on Dawson's Creek, nor do I feel totally at ease or put people at ease. I'm better off just having a nice, cold stout or porter, and putting my feet up.