I use a messenger bag, and load squishy items so that they'll be in an area without any weight on top of them while I'm riding. Things that might spill get tied up in a plastic bag.
Another fun trick (which I've done primarily with soft breads) is to use a plastic bag and actually tie it on the outside of my messenger bag (works with a backpack, too.) I keep a few plastic bags in my messenger bag, as I prefer to reuse them.
I use a trailer for larger grocery trips, though I rarely bring it on commutes.
Last edited by wipekitty; 06-05-19 at 07:50 PM.
Reason: forgot a noun