The following technique has served me well over the years. I have created a mapkey that does File/Save//File/DeleteOldVersions. It's mapped to the . key (del key at lower right corner of the number pad). It has just become a rhythm with me that every time I make a change my right index finger quickly finds that one nearby and easy-to-locate button, and I therefore almost never lose work. The fact that I don't save old versions makes this cleaner since I don't need to worry about purging clogged directories, but it will work as protection even if you don't use the DeleteOldVersions function.
