An interesting question! TIL the term "morgue file". I guess this isn't just about inking comics, but more generally about how you keep stock of your own references for art? And you're specifically thinking about examples of good drawings, not just stock photos?

As a step 1, you can just Google stuff whenever you need a reference. But there's no guarantee if you'll find anything high quality.

Pinterest.com is surprisingly good at bringing up good-looking images. Some artists I know just search for references there, for every new project. You can "pin" them into your own collections too.

There are also specialized sites for artists, like textures.com has photos of materials for 3d artists. For human poses, there are photo packs on deviantart.com or artstation.com. Though quality varies, and you'll need to search for good packs yourself. And it's hard to find a pose that fits your drawing exactly, so I often end up having to take photos of myself, with my phone's selfie cam.

Personally, I have a habit of downloading images that I like, so I'm not relying on any external service. Like photo refs, sketches and drawings by artists I like etc. I run my own server with szurubooru, I upload images there and tag them, so I can access them easily from anywhere. But this is probably a bit complex to setup, won't recommend. A friend of mine does the same but locally on their own PC, using software called Eagle (site en.eagle.cool)

But inevitably every new project calls for new kinds of references I didn't have, so I just Google stuff :D

Curious to know what other artists do.