Hey, I'm a Lux player. Let's start with the basics,

1. Try to use E on the group of mage minions, and focus on last-hitting the melee minions.
2. Ur ultimate is 60 seconds (1 minute) so don't be scared to waste it on an incoming minion wave. You may also use it for harrasing when you used Q.
3. When your doing really well. I suggest that you buy some wards because, their is a chance champions will gank you because Lux is very squishy.

Really hard to do. You must be good with skill shots. Buy some wards and, also make sure you communicate with your teammates.