To maximise your root duration R then Flash so you can get into range to instantly W. Upon arriving quickly E then Q your target into your R followed by some AA's.
Q also has a hitbox behind Maokai. W then take one step forward after arriving. Q away from your main target followed by quickly using R on enemies infront.
Q then mid animation Flash. Quickly W followed by an AA.
To make engaging easier Flash W instantly. Upon arriving quickly E Q, followed by R and some AA's.
One of the most effective trades starts with using E into a brush then W your target. AA as soon as you arrive then instantly Q your target towards your sapling and AA.
Engage a mid range fight with W then instantly Q R E as quickly as you can followed by some AA's.
To engage from further away R then E right before using W. Continue to AA until the root ends, then Q and AA again.
Quickly trade with W then instantly Q once you arrive and AA.
When closer to opponents Q W instantly then AA E once you arrive. Continue to AA.