Yeah, nami's a fantastic support with heals and cc but have you ever wanted to go ape****? To unleash the shark that lurks within your mermaid soul? Well here's my option for ya! Hunker down and hoist the sails, we're about to brave the waves!
This is still in progress and I'll update it as I go!

While Nami is a very very good support pick (I usually choose her if I need to pick first or if the enemy bot lane hasn't picked yet) due to her flexibility, good skills and lack of any hard counters, sometimes she's boring as hell to play. So I decided, I'd had enough of playing passive and wanted to style on the enemy bot lane and made this guide. If you too, want to style on the enemy bot lane or just want more poke dmg on Nami then this is your guide.

In this guide I'm mainly focusing on AA dmg than ability damage, but knowing how and when to use Nami's abilities is a very important aspect of this champ. I'm not going to go too in depth on her abilities, as there are better guides for that, but I'll give a quick rundown on how I mainly use them and what situations to look out for.

Ebb and Flow is the bread and butter of your kit aside from Tidal Wave due to how useful it is! You can use your adc, if they push up into the enemy to trade, to heal them and poke the enemy! All very useful things. If you're fighting the enemy in closer quarters you might get more mileage from Ebb and Flow by using it on an enemy to heal you or your adc. Ebb and Flow also, when it affects you or your ally, procs your passive Surging Tides for a speed boost scaling with AP.

Aqua Prison is Nami's Q. It's a very useful stun that affects a circle in a small radius around you, but it's a skillshot so landing them can be pretty frustrating. I usually use this to check bushes if I think an enemy is in them and use this defensively to protect my adc. If you can get an aggressive Aqua Prison off then power to you, but you might find your adc wasn't quite ready to follow and and nothing happens. In that case just use it to harass the enemy laners out of cs.

Tidecaller's Blessing is a buff cast-able on yourself and allies. Mainly, I use this as a cheaper Ebb and Flow for the speed buff granted by our passive, Surging Tides. It's still is useful for trading and confirming cs/kills, but mainly I just use it to get around due to the low cost.

Tidal Wave is probably the best thing in her kit, aside from Ebb and Flow due to the sheer amount of use it can bring in a teamfight when used correctly. It's also a very good peel ult and can save your team's lives. I usually use this for engage/ mid fight to turn the tables. You should be looking to combo this ability with Aqua Prison for up to a tasty 5.5 second stun or a minimum 3.5. The farther Tidal Wave travels the longer it's stun will be.

Nami isn't picky when it comes to adcs. She goes well with a majority of them, but does want at least one front liner in the team comp. (Don't play her with Kog Maw, it's not the best)
While Nami has no hard counter, she really doesn't like engage support. Especially ones with pulls. Your biggest threat will be a good Pyke, Leona and a good Caitlyn.
Pyke has way more mobility than you and self heal. Leona is Leona and is a pain in the *** to deal with (Ban Leona). A good Caitlyn is nigh impossible to trade with, but is managable.