For me, I currently use Firefox on my computer and phone, uBlock Origin and YouTube Vanced. What else is fairly easy to do that I can add on?
Switching browsers is probably the easiest with the biggest impact, but you’ve already done that. Switching your search engine to a privacy-friendly one is also a good step.
Run linux, trash iPhone, de-google Android, use a privacy-friendly DNS, Pi-Hole, …
I think YouTube Vanced is no longer supported by the devs and it was never a privacy-focused project anyway. There are plenty of FOSS Android apps that can stream YouTube more privately though. NewPipe is probably the most popular.
LibreTube is worth checking too
Like the others said, hardening your browser is going to be a good option. Additionally, a password manager is big too. I recommend BitWarden as its open sourced, cross platform and audited regularly. Security enables privacy, this is why you always see the two often referenced together. Standard Notes is another simple but powerful option. Like BitWarden its an open sourced and cross platform encryption based software. Emails are a big way to be tracked as well, using ProtonMail with SimpleLogin and/or AnonAddy is a powerful move but not exactly easy I guess
Use a different browser and search engine. I was showing my siblings some alternative search engines, and the first thing they commented on is that they all look similar. It’s not too hard of a step for people to take.