Small Lux idea: At levels 11+, Lux's basic attacks trigger Illumination in a small area
This could be a neat little buff for Lux's mid-game in letting her more easily kill creep waves. One big issue she has is that she can't oneshot lane minions without needing to use her laser (which is not advised if you don't have 40% CDR). This would at least improve her ability to clear out minion waves without reducing risk.
In team fights, I don't see this as being too game-changing, as Lux never wants to be in autoattack range in a team fight if she can help it.
And even though Lux COULD use her laser to clear creep waves, that's a bad idea if a fight breaks out soon afterwards, so she probably SHOULDN'T use her laser on minions. This change would let Lux keep her laser more for fights, unless of course she wants to vaporize the creeps with magical love. XD