Paucity of good speaking moments

I am a decent public speaker. Better at impromptu speaking. I practice as a Toastmaster in my corporate club meetings and other opportunities I get elsewhere. Out of 10 opportunities I feel good about 3 or 4. The rest I am not happy with. This could be the case of being too harsh on myself. Or expecting better. The thing though is that I expect myself to get better without actively doing anything about it. Feel that frequency of performances should automatically make me a better speaker. That doesn't happen. It helps in small ways but it doesn't make you a better speaker.

Of the 3 or 4 opportunities when I feel good. It is always because of better preparation.

I am talented in speaking. External validation also says. Though I don't necessarily put hard work into my speaking ability. I tend to rely too much oh the innate talent. It works some times but fails most of the times. This is the primary reason why I haven't been able to improve on my good moments. #Toastmasters