I usually use a drennan micro ring on the hook shank and bait floss loop with an granny knot secured in place with an overhand knot to stop it slipping... I'll hide the knot inside the popup when pulling it through with a baiting needle..
if I'm not sure what height to popup, the size of popup to use or even if I want to use a snowman or double popup... I'll use a variable length hair that requires no hair changing to facilitate any of the aforementioned baiting options...
hard to describe but I'll have a go... thread the line through the eye of the hook (just the once with no whipping around the hook shank) and secure it in place with a line aligner made from stiff rig tubing, use a small sliver of the same tubing on the shank blowback styly.. here's the neat bit, instead of using the drennan ring on the hook shank, tie it to the end of the single strand hair using a grinner knot... that's the rig complete and you'll be able to vary the length of the hair by pulling the drennan ring end to increase it or pulling the hooklink end to decrease it.. the key is to use the right internal diameter tubing to match the size of hook... larger eye, use larger diameter tubing, it needs to be a close enough fit so that it provides sufficient tightness to stop the hair slipping on the cast (it's easier than you think)... the drennan ring is just the right size for pulling through the popup with a baiting needle and acts as a bait stop to boot, the sliver of rig tube enables you to adjust the point along the shank from which to popup from as usual.
on a take, the hook is pulled along the hair until the drennan ring is pulled back towards the eye eventually pushing the line aligner back up the hooklink and jamming the ring in the eye of the hook.. sounds dodgy, but I've not lost a fish yet due to a problem associated with the ring pressing against the hook eye and I've had fish over 40lbs on this rig...... please note, I've specified drennan rings throughout as they are made from circular metal so won't severe the line when under pressure... other manufacturer's use flattened metal (think the fox one's are like this)..
a diagram or photo would have been better but a bit tired froma hard days graft at work so it aint going to happen tonight