Here's what I do for getting artwork for my music.
I use a combination of MP3Tag for tagging, and Album Art Downloader to get the album art. In MP3Tag, choose Tools, Options, and navigate to the Tools selection in the tree control of the Options dialog. In the Tools pane on the right, click "New" to create a new tool. You'll get a dialog with three things to enter: a name, which I call "Launch Album Art Downloader", a path, to which I navigate to AlbumArt.exe with the browse button, and a parameter. My parameter field looks like this:
"%artist%" "%album%" "%_folderpath%%album%.jpg"
This parameter specifies that Album Art Downloader be launched, automatically providing the artist and album name in the appropriate fields. In this case, the artwork for the album e.g. "Rubber Soul" will be downloaded to:
(directory containing Rubber Soul music files)\Rubber Soul.jpg
If you want the file to always be named, say, folder.jpg, the parameter field would look like:
"%artist%" "%album%" "%_folderpath%folder.jpg"
If using the first method above (that is, not using folder.jpg as the file name), it's important that the album name in your tags not include characters that are illegal in file names such as ":", "/", "\" and so on. A file name will still be generated that removes the illegal characters, but depending on how you configure your music player software, it may not recognize the file as the album's artwork due to the lack of match with the album title.
After entering these fields, click OK. You'll see a checkbox labeled "Use special program at double clicks". Check it, then in the combo box, choose the "Launch Album Art Downloader" name you created earlier.
Here's how the whole thing works. In Windows Explorer, right-click the directory containing the album you want artwork for, and choose "MP3Tag". This will open up MP3Tag with the music files from that folder. Then, just double-click any one of the song files of the album you want the artwork for, and that will launch Album Art Downloader with the correct parameters for the album and artist, assuming your tags are right. In Album Art Downloader, click the "options" link, which expands the form to show more options. Choose "size" in the "Group by" and "Sort by" fields. This will group the artwork so you can always get the best quality, or something close to your desired resolution. These options are persistent, so you only need to do this once.
Album Art Downloader searches a very large collection of sources for an amazing choice of graphics. For some of these, they will show in the "Unknown" size group. If you recognize an album cover in the "Unknown" size group as being correct, press and hold the left mouse button on it. This will download the file to a temporary, and it will then compute its size and correctly put it in the appropriate size group. I've gotten a lot of "best artwork found" results using the latter technique. When you find the graphic you want, just double-click it, and the file will be saved in the correct directory, with the name according to the naming convention you established in the parameter field discussed above.
I was amazed at how much I could improve my album art, but it was a lot of work.
Edited by andyc56 - 11/10/13 at 9:18am