Hi, I'm Chekko. A support main and this is my first guide. I'm not a professional, a streamer or anything like that. I've played the game since around 2011 although taken a long break mid 2010s and just been a fan of the game.

Nami is my favorite champion because I really enjoy her all-in-one style. If you dispite her inability to be a natural tank she has it all in her. Poke, CC, engage, disengage, peel, damage and even a bit of sustain.

Here are some tips on Nami:

Landing your Qs can be difficult. Try to Q the enemy adc as he goes in to last hit your minion. He either has to get a last hit at the pretty high risk of a suffering damage from you and your adc or escape damage at the cost of a last hit

Your E works on abilities too, your abilities as well. Especially with Electrocute you can deal a ton of damage by using E to empower your Q, W and AA to trigger both your E and the Electrocute. I recommend Electrocute against enemy adcs that don't have much mobility.

Don't forget your ult gives your passive the double movement speed buff. This is great for both engaging and disengaging

When you head towards lane you can use E on yourself or your ally to proc your passive for movement. If you got some extra mana regen you can use all your basic abilities to proc it for more movement.

PROS + Very adaptable + Great CC + Can shutdown champions + Helps her team chase down enemies + Great engage and disengage

CONS - Squishy - Weak heal - Q can be hard to hit

PASSIVE ABILITY

Surging Tides (Passive): Good for escaping or to get that boost to finish off an enemy. Your ultimate will give you double the movement speed

Q

Aqua Prison (Q): Hard to hit but worth it when you do. Your adc can follow up and you will do a lot of damage

W

Ebb And Flow (W): Your heal is not that strong and your poke from this isn't either. You can get a Redemption to compensate

E

Tidecaller's Blessing (E): Great for poke and giving your adc that extra damage in trades.

R

Tidal Wave (R): A great engage/disengage tool. It is quite slow and can be dodged easily in that sense, try to lock your enemy out of escape by aiming it a bit ahead the direction he is heading or position yourself so that your allies get the double movement speed buff as well

Mythics

Echoes of Helia Synergizes well with Nami's W, aggressive playstyle and helps you with her weak heal

Shurelya's Battlesong Your passive is good for movement but can't get you out of tight situations, that's what this Mythic can help you with. So with this you got two ways to disengage and even engage.

Moonstone Renewer The chain effect works well with your bouncing heal but this item is more towards safe supports so unless you are up against a hard matchup I would recommend Echoes of Helia instead

Enchanter Items

Imperial Mandate This is Nami's Core item in my book because it synergizes so well with her abilities. You can proc the passive with just your E on an ally. Great item for damage on top of your E.

Redemption A good item to compensate your weak heal with, both with its active and +15% Heal and Shield Power

Mikael's Blessing A goto item when the enemy got CC. Sadly the Harmony passive is disabled with Echoes of Helia where you get 25% extra health regen for every 25% bonus mana regen

Staff of Flowing Water Don't underestimate the Ability Haste on this item, this item can be useful even if you don't have any allies with Ability Power. Plus, the extra Ability Power is always useful on you.

Ardent Censer A great item on Nami as you can do a nice bunch of damage with a W+E combo to proc the passive together with your E which is pretty much the same thing

Defensive Items

Banshee's Veil Ability Power, Ability Haste and good Magic Resistance together with a nice spell block

Spirit Visage If you want a more tankier item against Magic Damage. A good Magic Resistance item against poke, though your teammates won't benefit from the passive

Randuin's Omen A great tank item against Physical Damage. The slow is not bad either.

Dead Man's Plate A good tank item Supports can use in order to survive some damage.

Summon Aery
Extra protection and extra poke, just what you need. A good Keystone overall

Manaflow Band Out of the three this is the best one, as Nami is struggling with mana. Her weak heal will make her heal a lot and that costs mana

Absolute Focus I prefer the extra Ability Power over the Haste, as I will have enough Haste already

Scorch Works well with your poke. Gathering Storm is a nice pick too if you want Ability Power

Biscuit Delivery You will be aggressive in lane and these will be good to have in your bag. Will help with your mana as well as health

Cosmic Insight Getting those summoners and items ready faster

Electrocute
Something that is great in the laning phase, but falls off later as shielding your allies is more important

Cheap Shot More damage. Works well with Scorch.

Zombie Ward A good Support rune

Relentless Hunter Again, a good support rune. I'd pick this or Ultimate Hunter

Absolute Focus I'd pick this or Manaflow Band but again, I prefer the extra Ability Power and you will be more of a burst than poke with Electrocute

Scorch Works well with Cheap Shot