Save often, Save always
Some people think of working on a computer file like writing a letter, when you finish the letter you sign your name. Unfortunately waiting until you finish a document before you save it can be disastrous. Of any advice I can give you the most important would be to save your work before you finish it. You should always save your progress and you should save it often. Anything can go wrong, you could experience a power outage, and if you have not save your work you will lose it.
I know there are auto-save, and there are backup saves if your computer does decide to shut down but remember it is a computer and you can not always rely on it behaving as you wish it would. You must depend on your self. So when you pause to rub your eyes or to think about what you will type next, hit the save button. You will not regret it.
Your PC Therapist