Extend the range of your R by using it, then mid animation Flash and instantly W Q followed by E AA.
For a tricky engage W Q at the same time towards your first target, then mid air quickly R Flash to hit your other targets. E AA your first target.
To engage on an entire team Q your first target and hit W mid air. As your reach your first target hit R and instantly F to hit as many people as possible.
When at short range Q E instantly then W AA once you land.
For a long range full engage Q then Flash mid animation. Quickly W R once you land and AA E AA afterwards.
When outside melee range W E together then instantly Flash Q followed by an AA
To gank Q your target, cast W mid air then AA E AA once you land.
While in melee range, W AA then instantly E Q followed by an AA.
To catch out the enemy team with an AoE engage, Q then R mid air. Instantly W E once you land.
When you are ganking post-6, Q and cast W mid air. AA E R instantly one after the other once you land followed by some AA's.