I often find myself in need of some new tunes, but who has the time to listen to everything? I've found one thing that works wonders for finding new music: listen to a bunch of songs through to the first chorus, then keep what you like.
I usually use Spotify's Related Artists and Radio features to do this, but really, anything works. The more important part is this: grab a bunch of new tracks and only listen to each track until the first chorus. That's it. You should be able to determine if you like the track (and the artist in general) in that amount of time. You'll hear the intro and the hook, and if you're not digging it by then you most likely won't. If you like it, add it to your new playlist and move on. If you don't like the track or the artist, move along (the faster the better).
If you do this for a few tracks and use that as the source of your radio (either in Spotify or something like Pandora), you'll be able to reinvigorate your library in no time — but with more precision than usual. You have to actively listen for a bit, but in the end, it's better than just browsing around, which will only net you fewer tracks for the time you spend.