Remember the First Rule of Gaming, at least in this household:
We've all learned this the hard way and sadly sometimes forget it.
Save and Save Often...
In my present game have at least 20 saves...
Saved games named for each town, updated on each visit, and keep two backup saves that I leapfrog when doing quests or exploring.
Also save before opening any chest or door, or right before dialogue options, this is so I can go back if the conversation doesn't work out well.