UPDATED: M3Unify v1.4.4
M3Unify is a flexible file exporter and M3U playlist creator that will allow you to off-load copies of your iTunes songs to a user-chosen location—separate folder, external drive, USB thumb drive, SD card and so on—the way you and your audio player want.

As you'll know from watching my AV presentation, I use M3Unify to stuff a USB thumb drive with music files to use in my car's audio player. It sure beats racking a mini CD collection to the driver's side sun visor. I still see people doing that. Retro.
This latest version of M3Unify now has an option to name sub-folders configured as "Artist - Album"; apparently, some audio players will only scan one folder deep such that files at the bottom of a folder hierarchy like Artist/Album/ will be ignored. Sad!
This is a free update for registered users. It's free to try with a 15-track limitation and $5.00 to purchase. More information and the informative video is on this page.
Play Counts Bug
There seems to be a fairly recent bug affecting track play counts--or plays--when the played count property of an iTunes track is changed with AppleScript. If iCloud Music Library or iTunes Match is enabled, the value will revert to what it was before being changed by AppleScript. It seems as though either the new play count for a track doesn't get synced to the cloud or that the original value in the cloud has over-written the new plays value. Or something like that.
Several scripts here (Multi-Item Edit, New Play Count, New Last Played Date, et al) that allow you to edit the play counts of your tracks are affected by this bug, which only occurs if you're also using iCloud Music Library or iTunes Match. I am not sure if versions of iTunes prior to 12.3.3.17 are affected or if, perhaps, the bug also occurs with a track's skipped count (I wouldn't be surprised).
I filed a bug report with Apple and it turns out it's already an open issue, so Apple knows about it. Now we wait.
No Script Joy for "Show composer in all views"
The new Get Info panel setting, "Show composer in all views" does not have AppleScript support, unfortunately. I suppose we can hope it might be added in the future. It can still be batch-set by selecting tracks and editing information for multiple items.
UPDATED: Dupin v2.10.2
I've posted a minor maintenance update to Dupin, the iTunes duplicates manager. I had to fix a minor incompatibility issue with how OS X 10.11 displays a Quick Look window.
Did you know that Dupin even used Quick Look? You can select a track in Dupin's track list, press Space Bar, and a Quick Look panel will display whereby the track can be played:
Comes in handy when you need to audition the tracks without having to locate them in iTunes first.
Dupin ($15.00) has many other features that will help you manage (and perhaps eventually Trash) your iTunes duplicates, like flexible dupe filtering, Re-Playlisting, "dead" track removal, and more. And it's compatible with iCloud Music Library tracks. This latest version (v2.10.2) is a free update for registered users.
iTunes 12.3.3 Released
Apple has released an update to iTunes that accommodates the just-announced iPhone SE and 9.7-inch iPad Pro. It's available from the Mac App Store under the Updates tab. Kirk has a rundown of new (somewhat minor) features.
Use Overcast and Join Together to Listen to Audiobooks
Marco Arment's Overcast iOS podcast app has been updated to v2.5. I use Overcast exclusively for podcast listening. It's fantastic. The latest version of Overcast has a great new feature: file uploads. Patrons of Overcast are allowed 2GB of cloud space in which to upload files up to 250MB each. This is a great way to get audiobooks into Overcast from iTunes whereby you can take advantage of Overcast's playback effects, like smart speed and voice boost.
And a great way to prepare audio files for upload to the Overcast cloud is to use use my Join Together app to consolidate the files of an audiobook to just a single file (or a small batch of individual files) under 250MB. In fact, it's likely you could get about eight hours of decent-sounding spoken word audio in a single audio file under that limit when it's encoded at 64kbps.
First, you need to be a patron of Overcast. Which means you've made an in-app payment in the Overcast app and registered. I'm an annual patron at $11.99 per year, but there are three-month and six-month patronage plans available also. Only patrons will be able to upload files to the Overcast cloud.
Use Join Together to create a Music file from a batch of tracks in iTunes (I had trouble with one m4b audiobook file created with Join Together and I'm not sure what the issue was. If I manually changed the extension to m4a in the Finder there was no problem.) Join Together will display the approximate final file size as tracks are dragged to it or the bit rate settings are changed. You want to make sure to keep your final file under 250MB (as underlined in red, below).
Also, since this file is only going to be used with Overcast, rather than add the final file to iTunes, you may want to use Join Together's Advanced Session Options (Option-Export) to save the final joined file to the Desktop. Once you upload it to Overcast, you can remove it from the Desktop.
When the appropriately-sized audio file has been exported from Join Together, go to the Overcast uploads webpage. Navigate to the file you created with Join Together and send it to the cloud.
Go to Overcast app. In Settings make sure "File uploads" is on. Refresh. Your uploaded file(s) should appear in "Uploads" at the top of the Podcasts section, where it will play like any podcast episode.
Just to be clear, I'm not affiliated with Overcast or Marco Arment. I just like listening to good stuff in a clever way on great iOS software.
UPDATED: Join Together v7.6
Join Together 7.6 will create and export a single AAC or ALAC audio file from the audio data of tracks dragged from iTunes or files dragged from the Finder, leaving the original source tracks and files intact.
This latest version will honor an iTunes track's user-set Start and Stop Times (which are accessible in the track's Get Info > Options panel), the presumption being that the abridged version of a track is how you prefer to listen to it. But this behavior can be over-ridden in the Advanced Session Options (Option-Export) so that the Start and Stop Times are ignored and the complete duration of a track will be incorporated into the final joined track.
I've also fixed a few minor bugs and done a little low-level maintenance.
The unregistered version of Join Together will operate in Demo Mode during which all of its features are available and unrestricted. However, in Demo Mode the volume-level of the exported file will be sharply reduced after a few minutes and through the duration of the file. A registration code for Join Together is $5.00. This is a free update for registered users.
UPDATED: Smarts v1.3.1
Smarts will save and store the criteria of an iTunes Smart Playlist — the smarts of a Smart Playlist — as a template so you can reload it into iTunes later.
This latest version fixes an issue with distinguishing between Smart and Genius playlists in modern versions of iTunes.
Smarts is a free download from the Mac App Store. More information is available on this page.
NEW: New Playlist from Selection to Folder
New Playlist from Selection to Folder will create a new playlist with the selected tracks in a chosen Playlist Folder—rather than at the top level where you'd otherwise have to locate it and drag it to a Playlist Folder.
Just select some tracks and then launch the script (you could assign the script a keyboard shortcut).
Enter a name to use for the new playlist and click "Continue...". A second panel listing the current Playlist Folders in iTunes will appear:
Select a Playlist Folder from the list and click "OK". The new playlist containing copies of the selected tracks will be created in the Playlist Folder.
More info and download is on this page.