Well hello there, i created account just to help you ( and i may actually wander around the site too but that doesn't matter for now). Anyway, first thing you should know, original "torso pieces" are actually bad for making good looking mocs, what you should be interested in creating custom torsos. Now, don't get me wrong, basic torsos are not bad thing, but to build more complex and better looking mocs you will have to learn how to do them. Now let me take you through a journey.
I cant post all links because its new account... same goes for images.
EDIT: Hey, this is Kahi; since you're adding a resource, I went ahead and added all of the links and grabbed some relevant images off the moc page. Hope you don't mind; I just hoped it would help the people using this topic out a bit more. Thanks for the tutorial!
This guy there is one of first mocs with custom torsos i ever made.
He may look impressive, originally he started as inikabuild (based on inika body, simple build without custom parts), but he will look funny compared to his newest version.
Theres 4 monts differenve between them and around 10 mocs.
All you need is experience, what you can put together, cheated connections etc. Its also important if you want moving and posable mocs or less posable but more impressive looking ones, i personally want all of my mocs to be posable, still looking for consensus between look and articulation.
Now, the femocs. Bane of mocers. First thing i would recommend you not doing is this:
Nuva breasts, also rahkshi heads. They just look ridiculous and over the top. Less ridiculous and more sophisticated shapes are better than big boobs and saying "That is female now, cuz it has boobs".
My newer femocs look like this (what is funny, my selfmoc is female):
Same race, completely different feel. Toa are a different story, example:
More petite and better shaping, less unnecessary boobs, moc doesnt have to scream "IM OVERSEXUALIZED FEMALE FROM PLASITC".
I hope these simple examples helped you, if I were you i would start with lego torsos and limbs, just adding technic pieces and armor. With time (and more attempts) you will get better. HF with building!