Have no photos right now, but want to mention that when I T-boned a passing car last October, I was returning from a grocery run. Luckily, the bike fell on me so it wasn't damaged. The fire dept. took bike and cargo to my place, just a few blocks away, and when I got home from the hospital, found the beer in the pannier/rack was okay, as well as the other groceries. Didn't even get agitated enough to foam over.
I use folding wire baskets in place of panniers, plus a trunk on top of the rack. The baskets work well, though they are rather cheaply made, and require bungees to stay folded up. I like that a full sized reusable shopping bag fits nicely within. I also stretch a bungee over the bag, running it through the carrying handles, as I have read a couple of complaints that groceries can bounce out of the carriers.I always tell the checker that I have my own bags, and will load them myself.
By the way, I often only have enough groceries to load one side. In my experience, off-balance cargo has no effect on the handling of the bike whatsoever.