I have yet to do my first harvest, so I'd get some other opinions, but I've heard of the "stem-snap" test, but also have been told that if the stem snaps, chances are it's already too dry and you should move to jars before the stem snaps.
I'd try to break up a bud like you were gonna roll a doob. If it's too moist to break up, I'd probably let it hang another day. If it's still moist, but seems to break up ok, I'd move it to jars to cure and keep an eye out for moisture. If you see moisture forming quickly, I'd probably move back to paper bags for a day. If not, just burp the jars as normal and let it cure for a few weeks.
If when you try to break it up it turns to dust or is dry throughout, it's probably already too dry to cure.