I use only 16 tabs for a straight play; I've found that for me, this is sufficient. If there is paperwork stored under a tab that needs further classification or there is a multi-page document under a tab, I use stickies on the side or paper clips at the top of the page(s) to keep them grouped together. I no longer use a tab titled "Contact" because I put all my contact sheets in sheet protectors at the front of my book and, if there are many I use
these to dentote differences and also to demarcate acts and scenes within the script. I don't trust stickies to stay put in the most heavily-trafficked portion of my book.
This is how I order them:
CALENDAR
BREAKDOWNS
SCHEDULE
ACTOR INFO
REHEARSAL REPORTS
PRODUCTION MEETING MINUTES
PERFORMANCE REPORTS
SIGN IN SHEETS
SCENIC
LIGHTING
SOUND
COSTUMES
PROPS
SHIFT SHEETS
MISC
BOOK
The first 8 tabs are mostly administrative/performance and the last 8 are geared toward production. I always keep my script in the back of the book. I also use a piece of sturdy cardboard, such as the one that comes in the package of divider tabs that keeps them flat and un-crunched during handling. It's glossy on one side so I use that side up at the end of my script. This way, the pages don't get stuck in the back pockets or create friction with the plastic and get all wrinkly. I hate that. Wrinkly pages...my standard binder is a 2.5" D-ring. I will never, never, never go back to O-rings.