Mnemonic techniques are okay, but won't you have to come up with a different one for every service you use? I mean if there's a pattern, then a breach in any one of them could compromise all your passwords.
I myself use mnemonic password for my master password. And I've started to make my passwords longer randomly generated ones. I use a file based password manager as well. I think that's a good mix of security and convenience.
I'm in the Newpipe bandwagon. NewPipe has been the best way for accessing YouTube for a long time on Android. It's available in f-droid. Another plus on my book. I'm kinda not so much into installing a random apk for revanced.