I use YouTube quite a bit too. I make playlists to keep track of some things, but I'll usually just DL tracks I'm interested in, and if I like the artist/tunes I'll buy the album, and everything is stored and organized on an external HD. As far as discovering new stuff, YT works similarly to Pandora with algorithms and past search history where if you play a tune it'll try to play similar ones, but I'll also supplement that with searches. For instance, if I wanted to find New Rock Music created after 2005, I'd do a Google search for "New Rock music" and then click on the "Tools" menu item (located just under the search bar) and then change the default "Anytime" to the custom dates I'm looking for. It's all based on ones ability to get creative with search terms.
Here's a few helpful links:
http://www.googleguide.com/print/adv_op_ref.pdf
https://www.makeuseof.com/tag/6-ways...ate-on-google/
Good luck and happy searching!