Hi there!
I've been eyeing email aliasing services like Firefox Relay or Proton's Hide-my-email feature for a while, but I'm cheap!
Well, that and I tend to like doing things myself whenever possible.
So after a bit of investigating I found out that using Cloudflare and a custom domain name, you can essentially get infinite free email aliases that get redirected to an existing email address (Gmail in my case, but I'm working on moving over to Proton at the moment).
One thing lead to another, and I ended up coding a Firefox extension to automatically inject aliases into email input fields using a custom domain name.
Because I find this whole setup cool, and am fairly certain that other people could benefit from it, I wrote up a full guide on my blog. I'm no Cloudflare or DNS expert, so feel free to point out any mistakes or make suggestions here or in my post's comments ;).
Note: Yes, I know that using a custom domain reduced the privacy benefits.