I am not an expert in the subject, but my all-time favorite non-fiction book is Comanches: The History of A People by T.R. Fehrenbach. All of my information is derived from this source. I'll let the mods decide if this is sufficient; if not, I expect this comment to be deleted. At the very least, this post should be viewed as a recommendation for further reading.

Comanches were a comparatively modern native culture that arose as a consequence of the introduction of the horse by colonial powers to the southern plains (primarily in modern Texas and northern Mexico). By modern, I mean that they adopted both horses and rifles as integral tools in their culture and warfare. The ability to accumulate horses was absolutely central to their recognition of stature amongst warriors. In other words, if you were involved in successful raids that resulted in death of your targets, accumulation of captives (which were frequently assimilated into their culture), or most importantly, the accumulation of horses (or as Fehrenbach quaintly calls it, "horseflesh"), then you were viewed as possessing great skill and/or "medicine" as a warrior. "Medicine" was sort of a catch-all term Fehrenbach used to describe a superstitious belief in the probability of success in battle. In other words, warriors with "good medicine" were believed to be invincible in battle, and if the tide ever seemed to turn against the Comanches in battle, then they assumed that their enemies must have had more powerful medicine. This trust in medicine resulted in somewhat bewildering results in battle. As an example, say a group of 40 Comanches were riding into a settlement of, say, 12 sleeping European pioneers (including some women and children) in order to ambush it. Clearly the tactical odds are in their favor in this scenario. But, if their lead rider (who is believed to possess the strongest medicine and is likely viewed as invincible) happens to be shot or otherwise de-horsed before the real action even began, then the Comanche response would be to assume that their medicine failed and they would all flee instead of continuing the engagement.

They did not possess a command hierarchy in the sense of distinct ranks like captain, lieutenant, etc.; rather it was just experience, wisdom, and success (or medicine) that qualified individuals for leadership positions in terms of planning and carrying out actual attacks.

As far as techniques go, they preferred guerilla-style warfare, including night-time raids and ambushes, which were often preceded by rallies by campfire in order to conjure up the best medicine possible. They were expert horseman, and a requirement for a warrior was the ability to accurately fire arrows from horseback. In addition, they were notable for possessing acrobatic riding techniques that permitted them to continue riding while slung along the sides of their ponies, basically using the horses as a defensive barrier against rifle or arrow fire.

They tended to favor ponies that were smaller, faster, and possessed great endurance. This permitted them to travel greater distances than their American, Texan, or Spanish enemies without carrying a lot of food or water with them. This is part of what permitted them to successfully extend their territory farther and farther south, particularly resulting in the Apaches being driven from Texas into what is now Mexico.

Comanches were very interesting in terms of the way they treated their enemies. They kept many captives who were often assimilated (specifically women and children), and did not recognize any sort of ethnic or genetic distinction with their members. You could be a blonde-haired blue-eyed full-blooded Comanche as far as they were concerned. They also raped and tortured enemies, and this behavior was not limited to the young male warriors. Fehrenbach notes that female Comanches were often very brutal in their treatment of captives, describing instances of captives staked spread-eagle along the warpath, with their eyelids cut off to face the sun, and with their genitalia mutilated.

Generally speaking, Fehrenbach seems to attribute their downfall to their concept of warrior currency. Basically, in order to gain stature, you had to continue raiding and stealing and bring in value. They placed no value on the maintenance of static wealth (and again, wealth here primarily means horse herds). As they grew and took over more and more territory, and as colonial populations grew around them, that essentially meant that young warriors hoping to gain stature had to start fights somewhat arbitrarily, and had to raid deeper and deeper into more and more populated areas that were increasingly better defended. Again, there was no cultural incentive to maintain their current wealth, and defense was never a relevant fighting strategy for them. As they continued to butt up against the expanding US Army presence, they just could not continue to compete, and eventually lost out as the US continued to expand.