Opt out of personalised advertising, reset your advertising ID frequently, use websites were possible in place of apps and any apps you do have review permissions regularly, go through your apps and turn off “learn from this app”, enable location services icon to see when apps are using your location, either use extensions to enhance your browsing experience that block ads and tracking or use a private browser such as Firefox (I don’t suggest using brave but others may vouch for it), set up a VPN for cases where you may need to use someone’s else network (protonVPN has a free tier but also offers premium options, rename your device to something generic such as “Bluetooth device”, by default your iPhone will probably be called YOURNAME’s iPhone as silly as this one sounds it’s worth changing as you aren’t advertising your first name over Bluetooth.

Hope this helps.

Switch to Android is a good first step. Being able to run verified open source software with F-Droid is a good first step!

The real response you’re looking for is to use Lockdown Mode. Be warned, it’s the nuclear option of privacy.

More here:

https://support.apple.com/en-us/HT212650

Due to Apples walled garden, its going to be difficult to nearly impossible. I know it's not the answer you want to hear but moving to an Android/ pixel system is going to be far, far easier and will produce better results. Sorry to be the bearer of bad news but that's the reality of the iPhone ecosystem.

Answers like mine are the most common for a reason. Don't ignore them, just take all the knowledge you can get.

My only recomendation to you would be to use your Apple phone with a pseudonym. All else is essentially meaningless. That's only partly true of course. Use privacy oriented services and not Google's or Apple's services, use a hardened brow- ah well... I suppose the only real thing you can do is change some settings so Apple reduces their data collection very slightly and keep your phone off most of the time (like shut down, not screen off).

There are better measures than what I described, these are not really suited for everyday use however. As an example, do everything on a third party cloud. If no files ever get on your system, Apple won't have that data on you. See how that is not practical? The one glaring issue is that companies track you, steal your data, take things they shouldn't, which will not be resolved on an Apple phone.

Nobody cares if it's "Jakes IPhone" when you share a hotspot. Changing that name would be a step towards anonymization, which does not really make sense if companies still know everything about you, like for example that you typed this message on your beautifully keylogged Apple keyboard or that you did, in fact, change the name of your device to something that is not your name. If they wanted, they could probably figure out why you did so with computational behavioural analysis, which has gotten quite common and really good.

The Apple ecosystem is incredibly locked down and limited in features. This is on purpose of course, as they make a lot of money with you. Not just with the purchase of your device. I do understand that you do not want to switch, likely because you "love the ecosystem" or "Android is buggy and cheap". And while both of these common viewpoints are full of flaws, especially when speaking for privacy, if you don't want to switch, well, please don't.

The sole reason why privacy oriented smartphones all use Androud is because, well Android and IOS are just operating systems. Both of them are incredibly polished and if I had to pick one of them for the sole features of it's base I could not. Android is open source however, allowing developers to actually make custom operating systems for their phones or for existing phones. On top of this, while Apple phones have exceptional security, Google's is best. By a landslide. Google is also actually quite tame in comparison to other phone manufacturers when it comes to data collection by the actual OS. They have Google Play services so why would they need to integrate it into their OS? Essentially every time they would change something in Android that would not be liked by many, they put it into the closed source Google services instead of the open source Android OS. This is simply because they are known to monitor, so they are sometimes pushed back and this is very often successful. Because non Google phones ship with Android they ship with google's and on top of that the spyware from the other company. Apple does not get restrictions often. If they do, it's by European law and Apple often finds ways around it. I would not be surprised if they made cables that have a certain ID that can be checked by their phone's chip and if that cable is not "up to Apple's spec" (they didn't earn money with it), then it won't work. To mitigate the Lightning ban. While this thought is really over the top, they do exactly this with the phone's components. This also means that EVERY SINGLE PIECE OF HARDWARE has a unique ID tied to you and all of those IDs are accessible by the OS. All of them.

Do you see why IPhones are shit? There's a reason why Apple is a trillion dollar company. If you don't like Google, use a Fairphone or some other device that supports /e/ os or something that works with Divest. I personally dislike Calyx as they fail to hit their mission goal but it's also a really valid option. There is nothing of value that IOS can do that Android can't. Do something for your own good. Ditch that rotten apple.

I assume this is the guide you're looking for

https://thenewoil.org/en/guides/most-important/mobile-settings/

You should check the rest of it out, there's some pretty interesting stuff

I’m also a privacy-focused iPhone user who’s not too knowledgeable, I hope you get a bunch of responses here. The only one here so far has been helpful

There is an ebook which walks through this setup with specific steps: Extreme Privacy: Mobile Devices by Michael Bazzell (not affiliated)