Geochemistry is a compilation of imprecise, irreproducible and uncoordinated analyses.
(i) Keep the rocks in mind, for they cannot be reduced to analytical measurements; (ii) (from O. F. Tuttle) minerals are the archives of the rocks; (iii) keep filing [your] fingernails while waving [your] arms.
Relatedly: a lecturer's assertion during my undergrad that fundamentally you cannot argue with the rocks [ergo any theory you develop must be supported by the rocks], hence in part this poem of mine; and the general feeling among my group's principle investigators that geochemistry is fundamentally characterised by paranoia, and how relaxed you're willing to be about cleanliness.