Best way to get better

[frc4321]

Hi, I'm new to the forum and to Re-touching. I've been a photographer for sometime now, and as photographer I really emphasize the perfection and elimination of flaws in pre-processing quality. However I feel like i'm hitting a glass ceiling b/c retouching I feel is the final push in producing quality commercial work.

In photography, I have spent 2 years simply assisting in everything I could, and I still continue to do so. By doing this I learned through diffusion and through picking up tips here and there by exposing myself to new situations and circumstances. Because of this, I consider myself a competent photographer.

My question is then, what is the best (not quickest or easiest) way to become a better more competent retoucher?

Thanks!