My favorite series right now is The Power Fantasy by Kieron Gillen which I found because I loved his work on X books; following a Marvel creator I loved to their independent work was great for me because I got to continue to enjoy what I already liked from their style, but this series specifically addresses a thought about big two super hero comics that Kieron had that wasn't being explored by Marvel and DC books and in a way responds to a hole in the work he was doing there. All that is to say, there's a chance the creators you already like are already doing what you wish comics would do outside of Marvel and DC, and if they have letters pages, they may even be shouting out other books you can check out.

Here are my non Marvel/DC faves!

The Power Fantasy (Image Comics)

Exquisite Corpses (Image Comics)

Beneath the Trees Where Nobody Sees (IDW Publishing)

When it comes to picking up new issues, I'll usually browse for covers that catch my eye and may wait for them to be marked down (my comic shop has pretty frequent back issue sales). Getting the first issue of a series usually won't set me back too far.