Nootropics are definitely an interesting topic of research. At one point I was prescribed Modafinil but discontinued use when it resulted in some undesirable cardiac effects. Currently I'm using a stack consisting of a variety of amino acids, minerals, and medicinal herbs.
I'm glad you mentioned goal setting/quantifying. With Cannabis use, it is important to establish intent when you are using. Why are you using at this time? To remove the humdrum out of daily household tasks, as something to be done in combination with meditation, to enhance creativity in writing or other forms of art? Without establishing intent, you lose motivation.
Finally, I have to wonder how much the lack of motivation has to do with the terpenes in the strains being used. For example, it has been shown that a strain with greater than 0.5% Myrcene will have a couch-lock effect and strains with Limonene will relieve anxiety and elevate mood. For those concerned with cognitive deficits, Pinene increases mental focus and energy.
When having access to the cannabinoid/terpene profile of the strain I'm using is considered a best practice in the industry, I'll be overjoyed.