I always shoot in RAW.
I am always quite surprised by people who do not know the value of RAW yet. By default, people tend to take pictures in a more familiar format, the JPEG.
Do you know that shooting in RAW will allow you to keep intact all the information collected by your sensor?
Using this format, you make sure you have everything you need to edit the image in post processing.
Working in RAW will allow you to easily rebalance your exposure to light and your white balance.
If you do not shoot in this format, it's time to start!
This format often makes it possible to exploit and reinforce certain shots that one might have forgotten and to make strong pictures of them.