So here is a picture of me from when I was about 6 years old. I do have a reason for posting this photo, so bear with me.
When I work with people, I inevitably find that they are pretty mean, critical or derogatory when talking to themselves or about themselves. They often learned this way of speaking to themselves in the abusive, dysfunctional or neglectful homes they grew up in. It is also pretty typical that when I ask them if they would speak this way to their child or their niece/nephew, etc. they can immediately recognize how unhealthy and inappropriate that would be.
How we talk to ourselves matters. One strategy to help combat this tendency to speak to ourselves in such a manner is to picture our younger selves. Hence the picture of me when I was younger. I have my clients try picturing themselves saying these same mean things to this younger version of them. That is much harder and more uncomfortable.
That little version of you, your inner child, can be a good image to bring up when we start getting down on ourselves. Instead of berating ourselves, it is useful to think of what that inner child needs. Often it is some version of comfort and reassurance. And as woo woo as that may sound, it works and it is powerful. So, the next time you start being mean to yourself, bring up in image of your inner child and offer them some comfort, you might be surprised how well this works.