Don't spam away his q too often especially in the lane phase . make every shot count, make sure it will hit the enemy champion because he is very mana hungry.

play aggressively in the early stage, as he is very good at harassing. take advantage of his passive, q-double shot can do a massive amount of damage to the opposing adc in the early game.
Also his ult deals huge amount of damage so dont be afraid to use it when enemy is not with low hp

Flash is the most used spell in the game everyone uses it as it can be used both defensively and offensively to reach or escape from an enemy champion. If you don't have flash you might be focus as the chance of escaping from a gank are low.

Heal is considered a "must" for The adc of the team as bottom lanes deals the most damage to the enemies. Heal is better than barrier as it canbe used for 2 players( you and another one near you) so is perfect for duo lanes

PROS:

Great laning phase

Deals a lot of damage

gap closer and escape


CONS:

Weak ultimate because it can be easily dodge or interrupted.

Low range

Passive

:its called lightslinger whenever lucian uses an ability,his next autoattack becomes a double shot meaning that it shoots two times dealing exta damage

Q

:its called Piercing light lucian shoots a bolt of Piercing light through a target

W

: its called Ardent Blaze Lician shoots a missile that explodes and forms a star, marking the enemies. Lician will gain extra movement speed if he attacks the marked enemies

E

: its called Retentless Puirsing which is a dash(small range). Lightslinger attacks reduce its cooldown

R: its called the Culling lucian unleashes a torrent of shots from his weapons