It may not be the prettiest sight, but I pack smaller items into shoes.
I use a small backpack with a zipper that runs the entire way around so that I am not digging for items. The same can be said for carry on rollerboards, but I find it less awkward to have a carry on that I can tote on my back. Then there are no worries about uneven sidewalks, plus I can use it to for picnics and any other beach items I might need, or as a day pack.
Pictured here is my swimsuit shoved into my sneakers.

