Lina

Light Strike Array destroys trees which can be useful against certain heroes.

Make use of Lina's long attack range to harass opponents in the lane frequently.

Light Strike Array when opponents are somewhat stationary, e.g. when they are going for a last hit or deny.

Dragon Slave is great for securing ranged creep last hits and harassing opponents at the same time.

Use Dragon Slave on creep waves to maintain Fiery Soul Stacks as you can hit more creeps consistently with it.

Lina is great at split-pushing and pick-offs due to high movement speed, great waveclear and damage burst.

Keep fiery soul stacks up in fights to ensure you dish out your maximum DPS with right clicks and spells.

With your Aghanims Scepter pick up, you can fly over treelines and cliffs to find better initiation angles or escape.

Lina's Light Strike Array has a long cast point. Look to dodge it.

Lina is a glass cannon type hero. Look to focus her in the fights.

Magic resistance and spell immunity items are great against Lina.

Gap closing items are good at getting you on top of Lina.

Lina is great at split-pushing and ratting. Consider getting Boots of Travel on a core.