Just to add something to Philipp’s nice tutorial. It is possible to customize the citation keys generated by Better BibTeX. For instance, the definition [auth][year][shorttitle:abbr:upper] would generate a BibTeX key like Christian2015SYH, which consists of the last name of the first author, publication year, and the first letter of the beginning three words of the title.
Also, it is possible to rename the attached document in a combined way with Better BibTeX. For instance, with the naming convention {%b_}{%t} in the Zotero plugin ZotFile, the document can be renamed to “CitationKey_Title”.