I recently picked up this small Corning ware bowl at a thrift shop. It's a good size for me as I do most of my baking/cooking in a toaster oven. (The regular oven does not work.) However it had a chip which is circled in the photo and it was a bit sharp on the inside edge. I knew I could fix it and here's how.
I have a nice little Dremel that comes in handy for lots for things.
I used the attachment that you see on it which has a rock like composition, rather like a sharpening stone. I could also have used the sandpaper tube you see sitting there beside it, either would work. If you use a Dremel, use the lowest speed and an extremely light touch or you could just make things worse.
This is the chip area after sanding, you still see the chip but it is no longer sharp.
Once my new bowl got scrubbed and cleaned it was good to go for my next casserole for one person.
I have used this method on several items and it works well provided you use that light touch. You could also press an acrylic fingernail sander into service if you have one and an old friend had a battery powered eraser that you could attach different tools in just like a Dremel.
If you have a drinking glass that get a small chip don't use something like the Dremel, but just plain sandpaper. My favorite tool is this:
Yup, a plain old nail file, super cheap and easy to handle. Take your time to go over the chip area to smooth any sharpness or roughness. You'll need to sand in several directions and use the smoothest grit for your final go. This is where a small piece of regular sandpaper would work best. You can even wet sand for a finer finish. I've saved several drinking glasses from being thrown out by doing this, but only if it is a small chip with no crack. If you get a crack, throw it out before someone gets hurt.