I don't know if this does what you want, but I use a ‘PROPERTIES’ drawer right below the subtree's headline and in that drawer, I put the following code:

:EXPORT_LATEX_HEADER_EXTRA: \input{latex-preamble.tex}

Scott Randby

Thanks for the suggestion!

It would still be nice (i.e., you wouldn’t have to do this for every section you ever want to export) to have a way of specifying a line that gets executed for EVERY (say) LaTeX export. Or else an option to do something like include everything in the file before the first section header.