Reduce your exposure

Before installing a new app or changing every setting, reduce the amount of personal information available across your accounts, public profiles, and old services. As a side tip: something I tell most people is to always use FOSS apps only on their phones. Webapps for (((social media))).

Start with account separation

Do not use one email address, one username, and one identity for every service. A single reused identifier makes it easier to connect activity that does not need to be connected. And it definitely makes you easier to have data leaks.

• Keep a primary email for important accounts. Compartmentalization is key. (Separating activities by browser, IP(proxy/vpn), or even in some rare cases and threat models, even entirely separate devices.
• Use separate addresses or aliases for lower-trust services. Or use them over TOR or Residential Proxies
• Delete accounts that no longer provide value. And definitely avoid apps where you can not even delete your damn data.JustDeleteMe is a gold utility for this purpose.
• Remove public profile details that are unnecessary.
• Check the TOS and Privacy Policy of services you use. You do not have to do this manually though, there are community maintained websites like Terms of Service; Didnt Read and also PrivacySpy.

Choose defaults deliberately

A default setting is still a decision. Review permissions, recovery options, public visibility, connected apps, and old sessions. There is a famous saying in the privacy community about this: A flashlight app does NOT need contact lists. And a (((fitness app))) does NOT need your geographical coordinates.

Opsec is not one product. It is the result of tedious, boring decisions that reduce exposure.

Use tools for specific jobs:

Tor Browser is useful when you need browsing sessions to be more isolated from normal activity.

Monero is a whole different beast entirely: understand its financial and practical trade-offs before deciding whether it fits your situation. Do note that it is one of the most anonymous cryptocurrencies you can own as well as an industry standard in the privacy community

Keep a short checklist

1. Remove unnecessary public profile information.
2. Change reused passwords using a password manager.
3. Separate important and low-trust accounts.
4. Review application permissions every few months.

The goal is not perfection. The goal is to make linking your activities more expensive and less automatic.