At level 6 is when you can start killing other champions! Start off with your Light Binding to snare them, then a regular hit to set of your Illumination, toss out your Lucent Singularity, explode that in their face and hit him with another normal hit to set off the second Illumination debuff. At this point they are probably low on health and running away, so shoot your Finales Funkeln at them (more often then not it will hit). Should be a quick easy kill. HOWEVER for tanks you may need to bind them again and toss out your E skill again to finish them off.

AP, AP, Magic Pen., AP, AP. that's the build for Lux is stacking your AP and magic pen so high it makes people cry when they see you. If you feel the need, when you're done getting the last item you can sell your Kage's Lucky Pick and but a survival item such a Rod of Ages or Banshee's Veil.