Well, you have to spot!!
But that isn't very easy and you can't do it perfect the first time.
You have to practise spotting.
This is one exercise, to learn spotting: (this is also how I learned it)
you have to take a spot straight before you (at the same hight as your eyes) then take little steps turning and keep your head as long as possible at the spotpoint, then when you can't keep your head there any longer (because yoúr body has turned to much) turn your head to the otherside and look again at the spotpoint.
take a person who wants to stand in front of you (about 8 steps away from you) with his finger up high as your spotpoint. You are going to take a step forward with your right foot (or your left foot). And turn (a whole turn over right shoulder, weight on right foot) while closing left foot next to right foot. In the turn you have to spot at the finger of the person who stands in front of you. You can do this as many times as you want without getting dizzy (if you spot at the good way), and you can also do this exercise as quik as you want and you can ad some arms in the turn.
I dance line dance for about seven years, but my spotting is not yet perfect, because I take my spotpoint to low and that is not so pretty. And I want to wish you luck with spotting. I'm sorry for my bad english. You can take a look at my website www.freewebs.com/dansjah
then look at the page movies and you can see me spotting in my dances.
Good luck with spotting!!! And turning