The profile selector for Firefox (I use Librewolf) is a nice way to manage different settings for websites that need to keep browsing data. You can also use containers but I find alt-tabbing more easy to keep track of. Foxyproxy is good for this

I run in impermanence mode with full LUKS decryption. I even hardened it further to require physical hardware for validation at boot. https://github.com/nix-community/impermanence

It’s interesting how easy it was to get used to.

Another project I like to use to verify the security properties of my OS is Vulnix. I have vulnix built right into my build script. Every time I update, I also get a full vulnerability report. To be totally transparent, though, I’ve been forced to ignore some vulnerabilities that are necessary evils for the niceties one tends to want in an OS. However, I might switch to Securix someday.

Anything that requires PII in a separate browser that doesn't clear on exit. General browsing on my main browser, which clears data on exit, except for a small list of exceptions. It doesn't defeat non-cookie fingerprinting, but I at least get rid of all the cookies that I don't want.

Shared computer? Clear Browsing Data on Exit.
Personal computer? irrelevant annoyance.

You should add permissions for select sites to store their cookies permanently. This reduces the annoyance dramatically.

I use two browsers. One remembers the logins and stores cookies. The other deletes all on exit. Its the beat of both worlds.

I do this. I just use a password manager that makes logging back in take 2 seconds, so I don't mind.

Use isolated browser instances instead. I want to be able to install useful addons for YouTube without having to worry if they're monitoring me when I'm online banking etc. All modern browsers offer this. And I use a mix of browsers for different tasks. Like Firefox for most things because of the ad blocking / privacy. But I still use chrome for compatibility as some websites are lazy.

I run my browser in incognito mode. Each launch a script creates a new profile directory specifically for that launch. When I quit the browser it deletes that profile directory.

For every activity, email, a specific search, an online purchase, an issue report, accessing personal information, etc., I'll launch a separate instance and within that instance I'll restrict my tabs to only that purpose.

I don't save passwords or bookmarks, both of which are stored elsewhere.

I'm not particularly worried about tracking by being fingerprinted, I'm much more concerned about data leakage, either inadvertently or maliciously.

Rebooting is an utter pain in the arse, but I put up with it and use the opportunity to clear my slate.

Edit: I don't create the profile directory manually, it's a little bash script.

I've taken to the habit of just logging in to the few sites I have accounts every time I open the browser. At this point, all my browsers are configured to delete all data. I don't find it an inconvenience, and I feel it adds a layer of security. I don't even use a password manager (though I should), as brain exercise I've memorized the few passwords I need. For me, it's definitely worth the slight extra hassle. However, I accept this may be a bit much, given I'm pretty much the only person who uses this computer. I just feel more comfortable flushing all those pesky cookies daily.

I use 4 different browsers and lock down each one depending on task… my general browsing browser is set to wipe every shutdown. The others only ever visit a single site.

I've been using cookie autodelete to clean crap from most sites, but whitelisting the ones I don't want to log back in every time

https://github.com/Cookie-AutoDelete/Cookie-AutoDelete

another advantage is that cookies are cleaned seconds after the last tab on that website is closed

It's a ton of hassle if you're logging into websites on that browser and I don't think it provides much benefit unless it's a shared computer and user account.

Firefox with uBlock Origin and Enhanced Tracking Protection enabled in strict mode blocks basically every type of tracker. You can add Cookie Auto Delete on top of that if you really want to make sure only sites you whitelist can save anything persistent like cookies or history.

If you're sharing the computer with others and you don't delete cookies after having logged in to whatever website/service that you were using, the browser could automatically log another person in with your credentials. This is because cookies can store "sessions". While I'm not a fan of Linus himself - and I do implore you to make up your own mind on that -, one time, at bandcamp, they almost lost their whole YouTube channel because their session tokens were grabbed, and they made a great breakdown of the incident, which can be educational: https://www.youtube.com/watch?v=yGXaAWbzl5A

I make my browsers either not save cookies at all or delete them on exit by default and manually tweak site settings for specific sites if and when I want to be able to log in "automatically".