E your target then W right before you AA Q. and right as you Q quickly R. Cancel it by moving towards your target as they are walking out of range for the last AA.
When dueling use W then AA twice and use E Q instantly, Flash away from your target at the start of your Q animation to safely R from range.
To all in after Level 6, W then instantly AA Q AA and finish up with E and R together.
The most basic way to maximise your R damage is to E on your target, then instantly R.
To normally trade E on your target, then W right before you AA and instantly Q AA after.
Use W then Q AA for an extremely quick trade.