Big Finish subscriber Short Trips, half hour audios that come with a Main Range subscription, have generic cover art that’s not quite square and doesn’t match the style of most BFAs. So I’ve photoshopped my own using the old Short Trips banner and public domain or NASA backgrounds.
Subscriber Short Trips for a given year should import as different tracks of the same album. If they don’t, you can group them manually in iTunes by using Cmd/Cntrl-I to “Get Info” and applying an identical album name to all the tracks you want grouped, then clicking the “compilation by different artists” ticky box.
Get Info is also where you can upload custom artwork. Feel free to use mine; just please don’t upload them elsewhere.