You should periodically measure your self-esteem
You should periodically measure your self-esteem. You can do that by taking various tests online, or you can take a self-esteem meter and measure yourself whether you're self-esteem is at a good level or not. Another mechanism to use in the extent of your self-esteem, is to give yourself points when you are doing things that are in in alignment with your goals and your values, and taking away points when you are not.
— from Who Is Flying (Self, Nature & Nurture)