It took me quite some time to come around to the fact that drawing from reference was not a hindrance to creativity but something that enriches your visual vocabulary. (BTW- I’m not going to delve into the whole “nothing’s new” argument, to which I agree here, and am just trying to keep it about the physical process of seeing and learning.)
Now to be honest, I still feel that if all you do is copy images like a xerox machine or human camera, that you’re not working up your form building or visual vocabulary as much as if you actively try to recreate what you see based on constructive methods. AKA, you look to the reference, but try to figure out what makes it tick, and what is going on in three dimensions in your mind vs. a 2D scan.
Building up forms is harder, and less rewarding than straight ahead, draw what you see type methods. Often it means making many horrible images and sketches before hitting any pay dirt. A nice side benefit to the constructive method is that you start to see way more relationships of forms in different subjects. They eyelid of a horse might bend around like the fender on a certain car etc.
So I came about to start using more reference and studying actual items and drawing from them from “the back door” so to speak. I was drawing forms out of my head as much as I could, and wanted to give them volume. So I studied some basic constructive methods (head is two spheres, arms are cones etc.) to help give my forms more volume, proportion and to be able to replicate them more easily across an image.
Eventually though, you run into the fact that your visual vocabulary for starting points is limited to these primitive shapes, and for organic forms of a certain detail, or things with complex and compound curves and intersections you need more vocabulary (or at least I do). Which is where I am now—trying to take my new constructive methods, and looking at as many kinds of reference as I can, build up my shape lexicon so to speak.
You can do this so many different ways, and while I knocked a little on people just doing the copy routine, I think ultimately it can get you to the same spot if you think about things a certain way. In the end, it’s just important to find the methods and workflows that keep you engaged and drawing/making forms that’s important.