Export to pdf
From Publication Station
InDesign
choose format> Adobe PDF (Print)
choose preset PDF/X1a:2001
choose the relevant or all pages
export as pages, not spreads, for single pages and booklets
if needed, you can add crop marks and export!
Illustrator
choose format> Photoshop PDF
you can select specific pages or all of them
choose preset PDF/X1a:2001
if needed, you can add crop marks and save!
Photoshop
choose format> Photoshop PDF
choose preset PDF/X1a:2001