Usual rule: Focus on Q the last hit for gold. E when farming under tower for last hits. Last hit, Melee minion when W ready, Q minion when W on cooldown.

Normal Ability order, R > Q > W > E.

Max Q first when top lane is passive farming. Maximize farming and poking.
Max W first when top lane is aggressive all in style (Xin zhao, panth), and farm under tower.

Pickpocket
Don't waste your Q on champion at before your Q is lv3. You would want to Q for farm. Instead, as they are heading in for last hit, auto-attack them once and back off for 5 gold. They should not be able to chase you down as your passive give you enough slow to run away.

Building your Tears of Goddess

When you are at base or walking back to lane, you have 2 self-cast spells, W and E. When at lane, Q's cooldown is quick and last hit refund mana.

You are now a solid front poker that is not afraid of getting poke, and also parrrley like a trunk in 1 skill shot.

Parrrley Poking

When: The build offer high mobility for you to lane that Q. Only poke with your W ready for CC break and the damage trade.
Who: Try to land the Q on ADC/caster, it hurts and they don't self regenerate HP like you do. We didn't build much armor pen, but ADC/caster don't build armor, so it is ok.
Why: You can't be kited. Your Q get you a movement boost, AND a 40% slow for your teammate to lane their skillshot/CC, forcing a teamfight.

Teamfight

When teamfight started, provided it's a 5v5, you have three roles.

1. R the area where enemy bruiser, that will slow the bruiser (and enemy's team) for your team to kite.
2. E giving yourself and team a damage and speed boost.
3. Continue to Q the ADC/caster (their highest damage dealer), while remaining in where your R is.

Split pushing

Providing your team stick as 4 man.
You should only do so with teleport up.

Enemy team will normally tower dive your team 4v5, but you have R to buy your team time to hide under tower. Aim R at where the minions wave is, killing off minions and slowing enemy to take more tower shot.
After your R, you should teleport in right away to support and finish the fight. With the split push lane's minion also push to their tower, your team can then dragon/baron.