I have garbage bags too, but for a much more selfish reason. They're for covering my bag in the rain.
I think it depends where you're going and what you're doing. At an unimproved range out in the back beyond, I'd probably take more than I would to a range in the city or to a match. I'm a match shooter, so I can only offer advice from that perspective.
I see two kinds of bag setups at most matches I go to. Minimalists, and kitchen-sinkers. Some people have little carts that they pull their bags around on, I s**t you not.
I take ears, eyes, lube, a few basic tools and cleaning supplies. A small rag and mag brush. Gloves, pens, a notebook, and all my reg certs. IPSC rulebook and RO overlays. Ammo as required.
One thing to think about when you're shopping for range bags is that a bigger bag holds more s**t and gets really heavy really fast. If you limit yourself to a mid size or smaller bag, you won't be hauling as much weight.
