I fill growlers and bottles from the tap with no problem when im going to parties/giving bottles out.
Never tryed it for longer but for short consumption:
Carb beer normally and turn down serving pressure to 2.
Install drip or get something to catch foamover.
Bleed keg till theres just enough pressure to push.
Tilt bottle at 45 and fill.
Watch beer line and make sure to get as high up the bottle as you can.
Close to the "commerical" level you see bottles on the shelf at and...
CAP ON THE FOAM
You loose 1-2oz if your good, have low pressure, and angle it right.
You can loose up to 4oz on heavier bodied beers.
Caping on the foam allows the headspace to be purged of all oxygen when you cap the bottle, this is very important to having it last and keeping carb at the right level.