The cornerstones of learning wazas involves two major aspects. One being the understanding the meaning of the wazas, and the other being Kihon.
Kihon is rooted in body posture, Jo-ha-kyu, Tenouchi, etc. The meaning of the wazas is regarding the Bunkai (scenario) of the waza. It sets the context for your body's orientations and actions within respective wazas, and may offer insights as to why and how kihon is done.
Let's illustrate with the traditional and basic seiza waza, "Mae". A basic observation can show the requirements of kihon - shoulders square to the front, back straight, chin tuck in, apply Jo-Ha-Kyu, knees in 90 degrees at end of yoko-ichimonji cut, and the list goes on.
What about the context? What's the basis for these actions? Again, with basic observation, one could guesstimate the "Mae" waza is related to one's imaginary opponent also in seiza in front of the practitioner. This sets the context for the prescribed actions in "Mae". The understanding of respective waza bunkai is important to help making sense of what happens when as a waza becomes more advanced (e.g. Shihotou and position orientation, but we digress).
A not so obvious aspect is regarding the performing of certain actions. Again, using "Mae" for discussion, one of them being slowly lowering back down to kneeling position from O-chiburi. Besides relating to the need for Zanshin, this particular exercise is intended to help the practitioner subtly train and develop the thighs and core muscles for more advanced techniques in the Iaido syllabus.
Because waza is waza, all actions in wazas are designed to achieve certain objectives, and the waza series were developed and arranged in progressive orders. Do consider this aspect and try to understanding the meaning behind the wazas; it will enable more a more interesting learning journey.
Til then, happy reading.