Most of the work I did to find new stuff was to find artist I enjoyed and check other bands the artist and production staff may be involved with. Check liner notes for any thanks or shout outs.

As a worker at an indie record shop in college I knew what most of our regular customers were into. I would watch the section new customers were looking at an throw something on the stereo I thought would fit. About 1/2 the time they would buy the album if they didn't already own it.

Edit: Your jazz story makes me think of two bands you should check out.

Galactic is a funk jam band with some great grooves.

Coolbone has changed over to Dixieland and Big Band jazz but started as a brass band playing live R&B and Jazz samples with both rapping and singing, their first album is called 'Brass-Hop'.