
Like the first two games in the series, Nioh 3 can feel a little fiddly out of the box but is easily improved through a bit of settings snooping. If you're diving into Nioh 3, I strongly recommend adjusting a few settings for the controls and UI, if only to try them out and see how you like them compared to the defaults.
On page 1 of the controls sub-menu of the options page, for instance, you'll find an option to "configure controls," and within that you'll find different templates. You start with option A, and I would suggest giving option B a try. This makes martial arts and combo extenders easier to use by tying them to the left shoulder (guard) button, and the only trade-off in my opinion is getting used to activating spirit skills with the D-pad. See how you like it.
I would more emphatically recommend poking through the game settings sub-menu. On page six, for example, you'll find options for auto-disposal of items and settings for which rarities you want to auto-dispose of (common, uncommon, etc.). I wouldn't turn this on immediately if you aren't used to the loot system or you're hellbent on farming an armor set bonus, but there may come a time where you don't want common or uncommon items clogging up your inventory, so these settings can become useful.
Nioh absolutely showers you in loot, which is why I also recommend trying the auto-pickup setting on page five of game settings. It does what it says on the tin: your character will pick up anything you walk over without any additional prompts or inputs. You'll save yourself a zillion clicks in the long run, and I personally don't find it any less satisfying. I actually like the rush of shiny items leaping into my pockets when I open a chest.

Another late-game consideration is found on page two of the menu settings. Here, you can increase the number of item shortcuts available – the D-pad menus in the bottom-left corner where you use things like elixirs and spells.
You start with two sets, or eight slots worth, but you can bump that to three or four sets. When you get a lot of different items and spells rolling, this can come in mighty handy. A technique I've found useful in the past is putting the elixir in the top slot of every set so you never have to cycle back to healing and you can still use nine other items or spells total, but your mileage may vary depending on your build.
Finally, have a gander at page three of menu settings. There are options for when and how to remove the "!" marks indicating new entries in main menus like your inventory, titles, and story progress. Nioh 3 hits you with a lot of tiny little updates whenever you find or complete stuff, and if errant exclamation marks bother you as much as they bother me, you may spend a lot of time cleaning them up. By adjusting these settings, you can very easily clear any notifications and return peace to the realm.
If there's something else bothering you about Nioh 3, it's worth investigating the settings related to it. Odds are good there's a way to customize it, and frankly some of the default settings have never made a lot of sense to me. Better options exist; you've just got to find them. Start with these and dial things in until they're just right.
Our Nioh 3 review has a full rundown on what makes Team Ninja's latest samurai soulslike great.