I'm in university now, so most of my music discovery is going to live shows and talking with my friends, but I used to be really into using the internet to find my music. My first stop was always either r/futurebeats or r/indiewok, but the turnover rate (especially with r/indiewok) wasn't fast enough for me. I started following youtube channels that showcased the type of music I liked: majestic casual and versimilitude mostly. Once I had a good list of artists I liked, I would visit their record labels' sites to check for new music from other producers on the label. For me this was mostly: Alpha Pup, Ghostly, and Ninja Tune, as well as wedidit. I also started following producer blogs like ISO50 a.k.a Tycho for further music discovery, as well as blogs about the genre like The Purple Bay. It's really about jumping from link to link that you find on websites.
As a fellow university student, I have to agree: most of the music I discover is from either live shows or talking with my friends. Normally during a party at our house, I'll put on Spotify through the speakers on my account, and give everyone free reign to fill up a playlist with their music. The next few days I'll listen to the playlist and I normally find five or six new bands I like. Contrary to the whole internet thing brendan suggested, I think the second biggest way I find my music is watching TV shows and adverts. I know this sounds odd, but some tv shows (Breaking Bad especially) have really good soundtracks, and looking up what the songs are can open loads of new possibilities for new bands. Ads are the same, although less common. Sometimes I'll hear an add and love the song, look it upm forget the product, remember the band.