For anyone who prefers mechanical pencils over pens (like myself), I have been extremely happy with the pairing of a Zebra M-701 and Uni Nano Dia HB 0.7mm on Leuchtturm1917 or Moleskine paper.
review: https://www.penaddict.com/blog/2012/3/5/rotring-600-drafting...
jet pens: https://www.jetpens.com/Rotring-600-Drafting-Pencils/ct/1109