Lux is a champion that requires you to be precise. if you never played lux before, you should go against bots a couple of times, just to make your aim a bit better. lux is also a champion that dont take a lot of dmg, so make sore you keep the other champions on a distance.

I find that when playing lux as a support, you take Luicent Singularity at lvl 1, light binding at lvl 2, and prismatic barrier at lvl 3. then you max lucent singularity and then prismatic barrier. (Ofc you take a point in ulti whenever you have the chance). leave light binding at lvl 1, till the other skills is maxed.
Lux's ulti is FINALES FUNKELN. when you get this down to 30-40 secs CD, dont hesitate on using it. it can make or break a teamfigth.
when in trouble use; Luicent Singularity (dont pop it), light binding and flash away.
when attacking; use light binding, lucent singularity, (remember to shield you allies if neccecery), and finales funkeln. (this combo have to come fast, cause they are only binded a short time)

I prefer flash and Clairvoiance (CV).
Remember to use your CV whenever you can, because it has only 75 sec CD.
try to save your flash till you really really really need it.

As you are playing a support, dont forget to lots and lots of wards. buy wards whenever you have some gold too much, or just do what i do, buy at least one whenever you are in th0e shop.

Give me feedback on how this build works for u. for me it works good every time :)
ENJOYYIYIYIYIYIYIYI