Right, that's me sticking to my Rapidex - these threadline things will never catch on!
Being reluctant to spend several quid on a bit o' plastic that ought to be free with the comics, I unship my cheapo fly vice from its clamp, push the stem of the vice through the centre of the spool, replace the vice in the clamp and wind away.Tension can be provided by impaling bits of foam each side of the spool, but being lazy and disorganised,I usually just wind gently and tension the string with my fingers. As most manufacurers seem to spool their line by turning the spool like a centre-pin, this means that your line lies on your reel with one turn of twist per coil round the spool, but when you cast, the line untwists as it peels off the spool and lies on the water "straight". IF you wind it back on using the same number of turns of the flyer, only possible if the line doesnt change length when you wind it back on,and if the clutch doesn't slip, this is repeatable indefinitely. If the line changes length when wound in - monofil under tension - or the slipping clutch is deployed, twist is built up.
If the manufacturer spools line up using a bale-arm and flyer like a fixed spool, you've got to figure out which way he's spooled it, which way you want to spool it, how to get from one state to the other,and how to get rid of the wretched stuff safely when you fail. This goes in Spades for southpaws like me who collect reels whose flyers turn left-to-right at the top. I've only been caught out once by this, but it was like trying to fish with a haunted spring.
If you load up "over the edge"and your spool size is identical to the spool the line came on, then the line will lie "straght" on your spool, but lie on the water in coils.When you reel in, the coils will tend to be pushed along the line by the rod rings; if this twist can't escape because your teminal tackle won't spin it will stay in the line until you slacken off, when it will do its evil best to turn into kinks.
Switch to braid, start saving for a centre-pin, beware of your slipping clutch, and good luck!