Sometimes I want to change the cover that a book has when it's imported into Calibre. I use the Download Cover feature in the Edit Metadata and choose the one I want. The chosen cover shows up in the Calibre library (in the Book Details and the Cover Browser) but is not attached to the book when I open it in the E-book Viewer and does not get sent to my device.
Clicking the button to "Set the cover from the selected format" just strips the downloaded cover from the Calibre file, so that's clearly not what I need to do. The only thing I've found that works is to click on Convert Books and then just click OK without changing anything. Then when I open in the E-book Viewer the downloaded cover does show up (and presumably will be sent to my device; I haven't gotten that far yet).
Is this the best way to do it, or is there some other method that I am just not finding? I often miss the most obvious things until someone points them out, so it's quite possible I'm just not seeing what's right in front of my face.