I've been using Mp3tag for quite a while now, and in that time I've thought of several things which could enhance productivity.
1.) Spacing Options. When renaming files, or acquiring data from a file name, you should include an advanced section which has radio buttons for the type of spacing the file name should have or already has.
For instance, in the file name 03 - Universe we see a hyphen. Instead of making us have to manually specify that this should be the type of spacing by typing it out, we should easily be able to click a button to select this.
If we have a song that has the metadata, but has yet to have the proper file name of our liking, again we should be able to easily click a radio button with our choice of spacing.
(quick note --if the advanced section is used, it should remain visible, similar to how naming is saved in Mp3tag. This would prevent us from having to show it all the time.)
2.) File Naming Conventions. This feature request is similar to the first one, but deals strictly with naming files. When naming files, it is often tedious to specify a new type of convention, like %artist% - %track% - %title% versus %track% %title%.
You could write down your conventions in notepad and copy/paste them when needed (which is what I do), but why make users have to do this? You should integrate naming templates which could resolve this and bring sanity to my mind.
3.) Auto Image Resizing. Do I really have to explain this? I'm sure many have experienced this... when their OCD tendencies kick in, because album artwork does not PERFECTLY fit into the equilateral square. I really dislike having to bust open Irfanview to resize images all the time when it can easily be automated with the quick click of a button in Mp3tag. If something is 520x500, just make it 500x500, or perhaps increase the size and allow the user to drag the image around until it looks good, then crop it (kind of like what Facebook does with profile pictures).
4.) Guided Album Artwork Acquisition. Instead of busting open a browser and doing a google search, why not just integrate a search option in Mp3tag?
Allow the user to specify the query text, as well as the resolution of the images they desire. Then show one-by-one each image it finds. If it cannot find the exact resolution the user desires, present them with the closest and ask them if they would like it re-sized and/or cropped.
(You should also allow them to choose to download the image into the album folder, and to specify the file name --e.g. Cover.jpg, Folder.jpg, etc. Integrated .jpg-to-.png and vice versa would be a HUGE plus).
I figure you could make the process quicker by only loading the text of a Google image query, and loading only the images of relevance. I know this can be done, because I am a programmer 
I have more features I would like to throw at you, but this will have to do for now. Any critique or comments are recommended. 
Thanks for reading.
