i'm using the word 'freehand' sorta loosely here...i guess i'll start by defining my 'freehand' process and then maybe you'd be willing to help a girl out with a better-fitting moniker?
i generally use this method of paper piercing when the project i'm working on just needs a little something extra to pull it together...it could be a flourish, a curly-q, or just a few strategically placed stitches to make an accent pop. these little (but needed) finishing touches usually make themselves known towards the end of a project after everything has become a permanent fixture...so i'll stare at my work for a few minutes, maybe make a few doodles on my sketch pad and then make the command decision as to what type of doo-dad i need to add.
using my pencil, i *lightly* draw whatever it is i want to stitch on my page/project...and the beauty of using a pencil is its eraseability :] if i don't like it, i erase and try again until i get the shape and size i want.
tip: flourishes & curly-q's...i like them to have a 'fluid & smooth' appearance, i've found that the faster you draw them, the smoother looking they are...i used to draw things really slowly and they ended up looking kind of choppy or bumpy-ish, so yeah, the faster the better for me...you should give it a try and see what works better for you :]
once i have my penciled in lovelies where i want them, i pierce holes, erase the pencil lines and then stitch away. here are a few layouts where i used the 'semi-freehand' piercing technique...
(above: i did some accent stitches on the flowers, freehand, and used the grooves in the petals as reference points...i also freehanded the white border around the scalloped paper. i pierced the 'valleys' of the scallops first and then pierced the rest as evenly as i could. below: the full layout.)