I had a similar discussion a few months ago
If you download the Stern Manual for Batman TDK, page 200 has every insert Stern uses
Not a fan of big inserts, The Shadow and Demolition man look bad to me. A big one in the middle of the pop bumpers might be acceptable
The very small ones look a little better, but not by much. Use if you HAVE to
I like inserts that are then shaped by the art, cat eyes on Bad Cats
Hotdog shaped, ONE, if the rest of the game demands it
Not a fan of the large arrows that Stern use, but I do like the arrows that F-114 Tomcat use (but will be a pain to cut out)