UBUNTU HOW TO REMOVE / REDUCE WHITE / BLANK MARGINS / SPACE ON PDF
In Ubuntu as an alternative to fineprint, page-crunch is suggested, but I don't find it useful, as multiple sheet printing is also available with the normal printing menu in ubuntu.
What is not available in page-crunche though is to put multiple sheets on one page and reduce the white space of each sheet.
To reduce the white space in a pdf use pdfcrop:
Use pdfcrop, see e.g. this blog
pdfcrop input.pdf output.pdf
To install it in Ubuntu
sudo apt-get install texlive-extra-utils
Then this pdf whitout white margins can be printed.
If you prefer a graphical interface for cropping pdfs use briss.
An alternative to that might be pdfbooklet, that also lets you create booklets.