Be comfortable in your own skin. Everybody has flaws. The serenity prayer says it best, (Abridged) "Change things I can, accept what I can't, and have the wisdom to know the difference." I know its a cliche, but its true.
The specifics of Inner game are different to each indivual, but I'll use another cliche, "if you build it, they will come."
Personally, my inner game lies in the fact that no matter what girl turns me down/flakes on me/plays/disses me, whatever etc. In my mind, I'm still one of the dopest lyricist of all time, I'm one of the youngest executives in a Fortune 100 company, I'm a shoe-in for MBA school once I do my GMATs, and I continue to accomplish the majority of the goals I've set for myself, almost on a subconscious level. I set goals, I know the goals, but I don't think about them and next thing I know I'm like, "Damn, I've always wanted to do that! Check that one off the list."
It takes time, but I knew I was there when I would could turn down pvssy, not come ons, but women who actually said to me "What would you say if I told you I wanted to Fvck you?" and "You have no idea what I'd do to you." I knew I was there when I started not going to the club on Saturday nights, had no pvssy lined up, but would rather prepare myself for the studio time I had set up on Sunday morning.
It was at that point, that I was truly comfortable in my own skin, win, lose, or draw I was going to "do me."