At the core of REBT (as I understand it) is Unconditional Self-Acceptance. This means not rating oneself at all. Accepting oneself unconditionally completely apart from what we do or do not do. Because we are complex, unique individuals, it is impossible to come up with an accurate method of rating ourselves (or rating others). We can rate our behaviour as good or bad, helpful or unhelpful, but we can not rate ourselves. We are ever-changing, unique.
If I do something stupid, for instance, I am tempted simply out of habit to berate myself: "I am such an idiot, such a buffoon, an imbecile, a loser, blah blah blah...!" When this happens, I stop myself. I recognize that what I am doing is rating myself, which is impossible to do accurately. I affirm that I am good, simply because I breathe. Every human being is equal in worth, none worth more or less than another. I remind myself of this, and then accept that what I have done is short of perfection. So what? I am not perfect; I am human.
I learn from my mistakes. I accept that I make them, and try my best not to make the same mistake again.
I could go on but I risk losing readers because of the length of my post.

I wanted to leave this with you all... below the cute photo below are some thoughts that are very useful in helping to achieve self-acceptance. I think this is key to recovery from AvPD.
Let's stop putting ourselves down!

---------------------------------------------------------------
THOUGHTS TO HELP INCREASE SELF-ACCEPTANCE
1. I'm not a bad person when I act badly; I am a person who has acted badly.
2. I'm not a good person when I act well and accomplish things; I am a person who has acted well and accomplished things.
3. I can accept myself whether I win, lose, or draw.
4. I would better not define myself entirely by my behavior, by others' opinions, or by anything else under the sun.
5. I can be myself without trying to prove myself.
6. I am not a fool for acting foolishly. If I were a fool, I could never learn from my mistakes.
7. I am not an ass for acting asininely.
8. I have many faults and can work on correcting them without blaming, condemning, or damning myself for having them.
9. Correction, yes! Condemnation, no!
10. I can neither prove myself to be a good nor a bad person. The wisest thing I can do is simply to accept myself.
11. I am not a worm for acting wormily.
12. I cannot "prove" human worth or worthlessness; it's better that I not try to do the impossible.
13. Accepting myself as being human is better than trying to prove myself superhuman or rating myself as subhuman.
14. I can itemize my weaknesses, disadvantages, and failures without judging or defining myself by them.
15. Seeking self-esteem or self-worth leads to self-judgments and eventually to self-blame. Self- acceptance avoids these self-ratings.
16. I am not stupid for acting stupidly. Rather, I am a non-stupid person who sometimes produces stupid behavior.
17. I can reprimand my behavior without reprimanding myself.
18. I can praise my behavior without praising myself.
19. Get after your behavior! Don't get after yourself.
20. I can acknowledge my mistakes and hold myself accountable for making them -but without berating myself for creating them.
21. It's silly to favorably judge myself by how well I'm able to impress others, gain their approval, perform, or achieve.
22. It's equally silly to unfavorably judge myself by how well I'm able to impress others, gain their approval, perform, or achieve.
23. I am not an ignoramus for acting ignorantly.
24. When I foolishly put myself down, I don't have to put myself down for putting myself down.
25. I do not have to let my acceptance of myself be at the mercy of my circumstances.
26. I am not the plaything of others' reviews, and can accept myself apart from others' evaluations of me.
27. I may at times need to depend on others to do practical things for me, but I don't have to emotionally depend on anyone in order to accept myself. Practical dependence is a fact! Emotional dependence is a fiction!
28. I am beholden to nothing or no one in order to accept myself.
29. It may be better to succeed, but success does not make me a better person.
30. It may be worse to fail, but failure does not make me a worse person.