I usually work with a combined FE and BE in the developer version.
For significant changes, I save a copy as mydb_1a.accdb or mydb_2a.accdb etc.
For minor changes,
mydb_1a.accdb, mydb_1b.accdb
I keep a copy of each iteration on the PC, and also copy each iteration to a Google Drive Folder, WORK/CUSTOMERNAME/
In the Google drive folder I have a Google Doc named
"mydb_Notes" where I keep notes about each database iteration and diaries my thoughts where necessary.
For really head scratching stuff I do a screen cast of the database, talking my way through a particular problem. This video walkthrough, is usually for my eyes only.
I save the video walkthroughs into the same Google drive folder.
I have a another Google drive folder which is shared with the customer. In this folder, I can drop video walkthroughs to demonstrate to the customer, particular features and/or progress reports.
If the customer prefers Dropbox, I do the same with Dropbox.
In the PC folder I create links to the Google Drive Folder and the Notes Document. This ties it altogether nicely.