For me self-forgiveness is a big thing that helps.

We are all human, and we all make mistakes on a daily basis. Really, its ok!

I think what matters most is how we behave after we make a mistake. Do we try and fix what we have done? (If we can.) Do we apologize to someone if the mistake affected them? (If its that kind of mistake.)

You can tell yourself "next time I'll try to be more careful so that I don't make the same mistake twice" and then work on improving.

I don't think any good can come of raking ourselves over the coals when we do something wrong. (I tend to do this myself.) I think self forgiveness is a big part of getting through these feelings and moving forward.