If I was smart about it I'd get one of those YouTube downloader scripts and attach it to something that puts on metadata and do it all in one step.

I do it in bursts and frequently it is motivated by reading something about music, then looking up the music on YouTube and listening to it there for a while before I decide something is worth putting in the library.

For what it's worth I am not particularly interested in music that came out in the last year or so, not like I am fundamentally opposed to it, but given that the event horizon for decent music recordings is roughly 1965, I think there is more older music than I haven't heard yet than there is new music.

Also my approach is album and discography oriented partially because I really like listening to albums and partially because it's often easy to get a whole discography. So it is not like I am keeping track of tracks I like as much as it is albums and artists that I like.