Vitality and Attack Power Farming Tips?

[SlacK CaT]

Whats the best way to farm for Attack Power?

[Don Lobo]

Running through and beating every boss. Farming Skill Points will become annoyingly slow, even in high NG+ cycles.

That being said, what do you want more AP for? After 14 you get diminishing returns, and around 28 extremely so. Almost any amount of time you could spend farming for higher AP is better used practicing better habits so you get better at the game regardless of your AP.

[SlacK CaT]

I wasn't asking about skill points - I just wanted to know about Attack Power-

[opus132]

The "best" route is kill Headless in the Ashina Outskirts.

He drops an item that upgrades your Attack Power using Spirit Emblems that basically has infinite charges considering how easy it is to get Emblems. He also opens up the path to the Bell Demon. This makes the game harder but also increases drop rate of items. Since you can turn it on and off at will at any point it's a good boost because you can turn it on when farming then turn it off afterwards.

The problem of course is that Headless is a very tough mini-boss and requires another consumable to kill (Divine Confetti) which is not hard to farm (it drops fairly regularly from the blue samurai in the Ashina Castle and those are easy to farm because they are easy to sneak up to, especially if you have Bloodsmoke Ninjutsu where you can even take two at a time with that) but it can still pose a problem.

So it's a catch 22. You need to kill an hard boss that requires a fairly rare consumable at the time you meet him, in order to unlock a way to get all the attack power boosting you'll ever need.

I don't know if you tried Headless already, but the best way to deal with his little disappearing act which follows up with that infamous grab of his, is to just unlock the target then make an 180 degree turn from where you facing and you can literally catch him in the "act". This gives you several free hits. On my profile i just uploaded a video where i do this on the Headless in Sunken Valley you can check it to see how i did it

[opus132]

BTW, Ako's Sugar can be farmed from the monks in Mt. Kongo, while Yashariku's Sugar can be farmed from spirits and apparitions. I think the nightjar ghosts before the Mibu Village are a popular spot.

[Alexoferith]

Hmm, skill points do have a direct relationship with Attack Power, AP, after you have collected all three pieces of a mask. First piece that you will come across is the character residing in a blue barrel, in the water. The nearest idol is the Estate Path idol or the very first Idol of Hirata Estate. It can only be bought with carp scales (I think it was 7 scales). The 2nd piece of the mask is sold by the vendor next to the Abandoned Dungeon Entrance Idol. It costs 5000 sen. The 3rd piece is sold by another character residing in a blue barrel, for 12 carp scales. And you can only locate this fellow in the FountainHead District, which means that you cannot go for the Shura ending if you want to get to him.
When you have a full mask, you can use 5 skill points to "purchase" 1 AP. However, as pointed out by Don Lobo, the higher AP you have, will not get you God mode like attacking ability. You see, each time you start another NG+ game, I mean NG++, NG+++, and so on, all enemies in the game will have increased in damage they deal, greater health and greater posture bar. The max AP is 99. You can reach this AP level, in general, around NG+7 or +9 depending on how much farming you can bear to do (farming for XP that is).
I did get to AP99 but my Sekiro was not GOD mode at all. In fact, it was quicker to defeat Owl the Great Shinobi at top of Ashina Castle during the first playthrough then at AP 99. He was so much stronger by then (NG+7 or higher), it will take many more hits to defeat him. So there you go.
Now, without the mask, the only way to increase your AP, is by defeating main bosses. There is NO other way. You will be able to get all 3 pieces of the mask in your first playthrough, provided you do not go for the Shura Ending (the short ending and most players reckon that it's the bad ending). it is becase the game is designed in such a way that you cannot progress any further in the game so you can never reach FountainHead district.
Getting AP 99 is just a novelty. There is no reward for it. Well, maybe self satisfaction :) Afterall, it does take a lot of patience to get that amount of XP. Google it. Someone did a chart for the amount of XP required for such endeavour. I had seen it myself (quite a few years back). It is no easy task. You may get bored and start to hate the game....
Have fun and good luck :)