Illustrator, Freehand or even Corel Draw are all vector-based programs that allow one to create postscript illustrations.
You still have to have the ability to draw whether using one of the above based with a Wacom tablet or the various tools available in the programs.
However, if you’re using predrawn images (like logos or other artwork) then you’ll get the smoothest lines by ensuring there are fewer points to describe perfect or half perfect curves/arches/circles.
Also, for output you need an imagesetter (or printer) that has postscript capabilities. A beautiful and smooth image from Illustrator printed out on a cheap ink-jet isn’t going to look as nice as one printed out on a laser printer.