[Illuminated One]

Make backups while you do the turn.
I always sort stuff first, then exit and save the files into a subfolder called sorted. Then I do all the other things connected to another area (military buildup, economic buildup, actual attacks) and save every time.
Also when you hit E the stuff you have done is saved and you can always do a few orders, end turn, do the next few orders.
Then when you make a stupid mistake and spot it you can quit without saving and go back to a fairly new save.