Gangplank is a hero which is hard to master. But when played correctly, it can nuke enemies in a quick succession. I used to play gangplank before the rework, but after the rework I stopped playing him. But, for the last 2 months, I am carrying my teammates with him and I have so much fun. Here is my build and tips to carry.

So, If you want to play with gangplank, you should learn how to use your E.
The most effective and easy tactic to use your E is this.
First, put a barrel in your Q's range. When you see the barrel going down to 1 health, just place another barrel near your opponent(s) and blow the first barrel up. This takes practice, but it will make you win lanes with massive blasts.

Gangplank has a very high potential in lane. At level 1, just poke your enemy and take last hits with your Q. Try and use your passive to secure last hits. When you are level 2, just use your combo to really hurt your enemy and hurt him/her back to base. Just keep farming and spamming Q at your enemy. If you use your E combo well, you can surprise your enemy with a massive blast which can lead to a kill.

Flash is your main spell.You should always take flash.
Exhaust can be useful in lane, it reduces the armor of your opponents and makes you take less damage from the exhausted opponent. It can also be used to secure a kill after a blast.
Ignite can be useful with GP, but if you have any concern about your lane opponent, take Exhaust.
Cleanse can be a good option if you suffer from hard cc's on enemy team.

Your Passive, Trial By Fire, Burns your opponents with true damage and gives you movement speed. You can hit your enemy with your auto attack, than use your barrel combo which will refresh the cooldown, than go all aggressive and finish off your opponent.
Your Q, Parrley is your main poking ability. You can use Parrley to blow up barrels. In lane, you can spam this ability to farm, which will give you money to upgrade your ult, or you can spam this to poke your opponent.
Your W, Remove Scurvy gives you Health and removes all CC, so you can use it against hard stuns or snares.
Your E, Powder Keg is your main damage ability. It deploys a barrel which has 3 hitpoints and when destroyed by Gangplank, it blows up, giving AOE damage. You can use it with your Q and trigger multiple blasts by chaining them. It gives you a MS boost and slows down enemies in its range.
Your ultimate, Cannon Barrage is a global skill. It can be upgraded and it has massive potential. It slows down enemies in its range and it can be used to secure kills.

In TF's, just use your combo when your enemies are grouped up. Finish off with your R.
Don't be afraid to use your R to save your teammates or helping them secure kills.
Your passive gives you movement speed. After engaging with your barrel combo, just flash in and finish off with your passive.

Gangplank can be used to nuke down groups of enemies. If this guide helped you, please vote for it. The Flames Are Calling!