Use Sonic Wave before Dragon's Rage so you can chase the target with Resonating Strike.
Take advantage of Flurry by weaving in basic attacks between spell casts - this maximizes damage output and minimizes Energy loss.
Self-casting Safeguard and using Iron Will are powerful tools for killing neutral monsters (in the jungle).
Stay spread out to minimize the impact of Lee Sin's ultimate, Dragon's Rage.
Lee Sin has powerful tools to combat physical damage in Iron Will and Cripple but he is still vulnerable to magic damage.
Lee Sin relies heavily on following up with his abilities. Use disables to prevent him from chaining together his abilities and attacks.