I can stuff some bills in the mini-wallet I carry. Coins mean they're either rattling around in my pocket or I need to carry some sort of coin purse. And, when I travel, I end up with this bag of unfamiliar coins that I'm trying to figure out at the counter. (Though I use cash when traveling at fewer and fewer places these days.)

I typically keep $2 bills as the smallest denomination in my wallet, with a couple of half‐dollar and dollar coins.