Aiight so the basic skill sequence is pretty simple,
EQW thats pretty much it. This is basic harras.
In team battles you wanna E so you jump in the battle fast and press Q so that you can lower their defense, then you can either R to buy some time or save your team mates.
I pretty much say that your nimbus strike is the best harras and thats why I max it first and rush to crushing blow because it works well with nimbus. Decoy is pretty much the same at any level but you wanna make sure you have it at 1 before you get to level 6 just in case of ganks or unsuccessful ults.
After you ult you want to constantly try to harras them with your EQW EQW EQ EQW whenever possible really.
Most people realize that when they are getting gank and have their decoy down, Ult is your best friend because it gives movement speed and toss up if they touch you. Use ult to initiate or run out of battle. Remember don't decoy to obvious spots like a grass sometime time its best to run back or run behind the enemy. For instance You decoy bot and they are attacking your decoy and wasting every CC they have, You can decoy to get behind them and wait for the perfect time to kill squishies.

For items, I start with dorans sword because i want that edge when in lane and i want to deal alot of damage at level 1 when i harras. I then move to berserker greaves because of the attack speed. You can replace it ionian shoes or merc treads. I then move to sheen because When i harras with my nimbus, Im going to use crushing blow and i have space for one normal attack without them getting away. After that I rush warmmogs for a special reason, Most people say that Wukong dies to fast or is to weak. Warmmogs increases my life by a ton and is great with atma's Impaler. For my second to last item, I chose black clever for one special reason, and that's because after you harras and you ult, you would do really little damage without clever but with it you already reduce their defense and can deal alot more damage. Last whisp also stacks with this so that means if you fight a tank thats full armor, it wouldn't make a big difference because the damage ratio is still high. If you made it this far and the game continues, Drop berserker greaves and make Phantom danser if you can and only do this is you have enough money to afford it from the bat instead of building it slowly.

I use flash to get in or out of battle safetly or i can pop in with my ulti and screw up the other team. Ignite is great in beggining and can destroy. You can replace these with Ghost or exhaust it's all up to you

Like title says ahahha i'm aware that there are better builds but this is the build i started with and i didn't have a problem