Mid Lane - I always get first blood just focus on minon farming
and harass when possible and go for the kill when its safe.

When going back to town make sure you harass your enemie lowering his hp until your return. teleport is replaceable by ghost to return to your lane.

Earning exp and farming early game is important with lux.

Lux is a excellent support farmer and ganker.

Take advantage of her passive - after binding someone, quickly throw your E on him or in his way of escape but do not active it to explode until you have hit him with a basic attack triggering from your bind skill once her passive is activated then explode your bubble and trigger the passive once again will delt a good deal of damage.

9-21-0 works also for extra hp but besure to get lichbane so that you can make an escape with the extra speed. people believe lux is a very good support champ but she is not only a good support champ but a Burst Damage Dealer.

Shield your team before going into battle that will cost enemie 1 skill wasted
if possible bind and bubble slow the enemies squishy, once binding there damage dealing squishy use her ult and try to hit as many as possible lux ult is no joke vs squishy will and can deal up to 40-70% of there hp depending on which champions.

Shield your team as much as possible stand back into the clear or side if the enemie try to come at you run around your teammate but do not stray away in panic.

Pros

-High Burst magic damage
-Easy to minon farm
-Spammable skills due to nice mana regen
-Long range harassment
-Delaying Fights (in depending team fight you dont want to over extend but with lux you can keep spaming your skill to lower your enemie hp until someone initates

Cons

-Not much cooldowns - you can wait 1-2 more seconds.. not going to kill ya ;p but sometimes it does lol
-Lack in magic pent (Magic pent is good but she can already kill other squishy if her combo are done correctly and her skill Cooldown are a bit long she not ment to kill tanks just bind/slow enemies and help deal damage, killing tanks are for dpser. no need for much magic pent when your just aiming for squishies)

After LichBane you can hit and run pace out your attack like example

Bubble+common attack you'll deal 300-400 dmg from bind+passive 100-200 +lichbane 500dmg physical.

wait 3 seconds then bind + ult + common attack that instant 2.5k-3k Dmg you can kill almost any squishy