Wukong is an excellent solo lane champion, with a combination of burst damage, durability and difficulty to gank.
His basic harass method is closing the gap with Nimbus Strike, autoattacking with an immediate Crushing Blow afterwards, and then using Decoy to avoid retaliation.
However, be aware that relying on Decoy in this way will drain your mana quickly, leave you without your main escape mechanism should you be ganked, and make relying on the same combo repeatedly with Wukong makes you predictable.
Leading with Crushing Blow will reduce the opponent's armor, increasing your damage output.
Crushing Blow resets the attack timer, using it immediately after an autoattack will give you a 'free' attack.
Both Nimbus Strike and Cyclone allow Wukong to close the gap between him and his target.
Using Decoy is an effective way of escaping and chasing down enemy champions.
When fleeing, consider how best to utilize the brief stealth provided by Decoy. Use it to juke your pursuers by changing directions after using Decoy. Sometimes it's best to simply stop after casting Decoy and watch as your opponents continue to chase in the direction they think you've gone, this is known as 'stop juking.' By pressing "stop" [default key: S] you can pretend that you have used Decoy to make your opponents think that you are the decoy. However, this move may not work on skilled opponents.
This is less effective against more skilled opponents, because the Decoy doesn't show any visual effects ( Blessing of the Lizard Elder/ Crest of the Ancient Golem buff, Oracle's Elixir, Poison, Mordekaiser's Children of the Grave, etc). This means it is usually easy to tell if Wukong has really used a decoy or not. Though if the foes do not have any stealth revealing items, then the real challenge is knowing where to retreat as your enemies search for you.
When ganking an enemy from the brush, use Decoy while inside and approach your target during the stealth time.
The Decoy can also be used for farming on minions for multi-tasking, as well as tacking up damage on champions via a flank or a "personal gank" if the player is skilled enough to take advantage of the situation without any risk (i.e.: putting a decoy in front of a foe's escape path, forcing them to take extra damage with correct timing).
Decoy can be used as a shield against skillshots such as Caitlyn's Ace in the Hole and Blitzcrank's Rocket Grab. Decoy always appears behind you. Thus, it can be used as a utility shield for all sorts of situations if needed, such as stopping ultimates to save either yourself or help allies retreat.
It can also be used to stop Rammus's Powerball.
If Decoy is used exactly when Karthus's Requiem hits, the damage will be nullified or taken by the decoy.
Decoy can also be used to gang up on opponents; with careful timing, it's possible to add up the decoy's attack to his burst damage in a one-on-one fight.
Crushing Blow's bonus damage works on turrets and inhibitors.
Crushing Blow's effects now grants additional 125 bonus range which is good to finish an opponent who is just slightly out of your range.
​Because of the bonus range, Crushing Blow can be used to punish melee opponents who try to last hit safetly as well. A Nimbus Strike can be used right after it for some extra damage and to ensure a Decoy or Cyclone followup for more mindgames or heavy damage.
Cyclone is not a channeled ability so crowd control effects, like stun, silence or knockback will not cancel or interrupt his ultimate. However stuns or snares will prevent him from moving. However, reckless use of it can be suicide, as Wukong can't do any other actions other than move or use certain summoner spells while spinning, so use with caution.
General team fighting with Wukong should aim to persist in the fight as long as possible utilizing his skills multiple times while also disrupting the enemy team and not getting focused down. Such an approach is to use Nimbus Strike to close on a dangerous enemy, autoattack, use Crushing Blow for another attack, and then immediately use Decoy since enemy crowd control and burst may be headed your way. While stealthed, you can back off and reposition yourself. Then re-enter the fray with another Nimbus Strike and another Crushing Blow before activating Cyclone to disrupt their team as they come after you knowing you don't have Decoy available. After Cyclone finishes, you should be close to having Nimbus Strike ready again to chase down an enemy or smartly target to aid your escape.
Try to hang onto your Cyclone during teamfights instead of using it to initiate fights, your visibility with your ultimate and high damage output will put focus onto you from the enemy team. Instead use it as a strong crowd control to break up enemy champions and to chase.