LST is the shit yes, and when i did my first grow i tied em down a little too early but they ended up doing fine.
How old are they? Dont do it before 2 weeks for sure. I would say 3/4 weeks depending on growth/stretch.
Make sure your lights are 2ish inches from the plants if your using CFLs
Also halogen lights are no good, if you meant HPS then yes keep it a little ways off you will have ample light penetration compared to CFLS and you wont cook them.
But halogen wont give your plants enough of the right light.