For Lux i like to play with full ability power so your spells would deal high damage to enemy's.
I like the ultimate because it got low cooldown and is OP too.
this is my first build so i hope you like it

pros:


+amazing range
+early game harrasing
+fast minion farming whit Lucent Singularity
+easy laning and playing on mid

cons:

- squishy
- uses much mana
- spells got a long cooldown early game

For masteries I take 21-0-9 to get full profit out of the abillity power bonusses

For runes I take 3 Greater Quintessence of Potency, 9 Greater Glyph of Potency, 9 Greater Seal of Clarity, 9 Greater Mark of Insight.

Greater Quintessence of Potency
I chose these Quints because they give a really nice amaunt of AP, which allows you to do more damage earlier on enemy's

Greater Glyph of Potency
i chose these Glyphs because of the same reason of my Quints

Greater Seal of Clarity
Lux uses much mana so that's why I choose to take these runes. if you like to spam all your skills then the mana regeneration runes are handy.


Greater Mark of Insight
These magic penetration marks are usually for any AP based champion so i think that it is good for Lux too.

Illumination
Q -Whenever Lux hits a target with a spell, they gain an illumination debuff, Lux may then detonate the debuff with an auto attack to do extra damage based on her level . Her ultimate can also detonate the mark.

Prismatic Barrier
W- Lux throws a wand giving shields to every ally, and also re applies the shield if it hits the same champion on the way back . You also get the shield when you cast the spell , and when the wand returns .

Lucent Singularity
E- This is your main farming, scouting skill.
i use it to check brushes, and for slowing enemy's, i do everything with it. I max it first.

finales funkeln
R- A long range, laser.
This has got to be one of the most fun ultimates to use in the game!
and the best of the ultimate is that the cooldown is very low!
However , if you want the cdr or not , is up to you.
Amazing finisher spell .
A good minion farm spell

Lux Needs to follow a certain pattern of spell casts to do maximum damage .
First of all , start with Lucent Singularity and right after throw a Light Binding follow up with one auto attack, detonate Lucent Singularity and throw in Finales Funkeln for the last damage

For summoner spells I take Flash and Ignite

Flash if you are almost dead you can always flash away to stay alive. and then cast a Light Binding

Ignite just a little spell to finish them or just to deal more damage early game.