Instead of focusing on what you perceive as negative about your body ("my stomach is too big and flabby"), recognize the positive attributes instead, such as - "my stomach may not be as toned as I'd like, but my core is getting stronger every day".
Of course this requires consistent exercising towards such a goal.
I truly believe if you practice such a 'ritual', you will realize that your body is capable of so many things, and you’re much more than just a number on the scale, or a size on a tag.
Negative: "I don’t like what I see in the mirror".
Positive: "There are lots of things to love about myself. I am working on it".
To achieve self-acceptance, practice complimenting yourself. You are beautiful, we are all!