Years ago, a WGI judge at a seminar mentioned that his most common critique for a remedial colorguard was that they rarely knew how to stand. The group would come in, unfold their floor, set up their equipment, and then stand with slouching and widely-varied postures, waiting for their music to begin.
In my own limited experience as an adjudicator, I have found that I often have very similar complaints. We are supposed to be judging your show, but rest assured, we are judging you from the moment you come into our view. If your ensemble cannot stand with "good" and consistent alignment, then I have already decided what kind of show I'm about to see, and you will have to work very hard during your performance to change my mind.
If you noticed that I put "good" in quotations, it's because there isn't really a universal consensus on what "correct" alignment is. Different traditions of dance have different ideas of what alignment should be. Here, I want to discuss the two that I believe to be the most useful in a colorguard context.
I teach TWO kinds of alignment for colorguard, and encourage my students to use both. Each has its own application, and I find it often useful to be clear with my kids about what they should use in each of their basic exercises and in the context of choreography.
Alignment #1 - "Stacked"
I often call this "Ballet Alignment" with my kids. If you start in an open first position, begin by spreading the toes and feeling a wide base through the balls of the feet and heels. Envision a spiral wrapping up from the arches of the feet, gently supporting the turnout of the knees, and allowing the femur to rotate outward, creating a wide feeling across the front of the hips, and feeling that spiral end by rotating into the supported crease right under the glutes. Don't clench the glutes, but allow your core to support your spine in front and back while maintaining the natural curve of your spine. Allow your head to float upward, creating easy space between the vertebrae. You should feel your scapula low and your back wide as the ribs stay neutral. I like the term "quiet ribs;" they feel easy and spacious as you breathe deeply. Focus is straight ahead. I like to think of this as an "active" first position; constantly spiraling, feeling unnecessary tension release, and allowing micro-corrections to take place. (My thoughts on an "active first" deserve an entire post! Look for one in the next few weeks!)
I find this alignment very useful for basic dance exercises. Colorguard often puts dance exercises that might traditionally be performed at the barre, in the center of the floor. I think it's helpful in that context for students to learn the balance and control that this alignment offers. I also like to remind them that turns are much easier using this "stacked" alignment, as are many jumps and leg extensions.
Alignment #2 - "Performance"
Because in colorguard, our audience is very frequently above us (as opposed to dance performed on a stage with the audience slightly below or directly in front of the performers), performers are often told to "project to the box." Without specifics as to how best achieve this, many performers will default to hyper-extension, over-stressing the neck, splaying the ribs, causing unnecessary tension in the back, pinching the in the lower back and hips, and tilting of the pelvis. The long-term effects of this on the individual performer can cause both pain and injury over time. In the short-term, with this limited direction, the ensemble will display a wide range of postures. Such variation becomes easy pickings for any judge looking for consistency from person to person on the floor or field.
The second type of alignment I teach is simply a variation on the first that addresses this need to "perform to the box." Once the "stacked" alignment has been achieved, the top half of the thoracic spine may be arched slightly backward in a position similar to a small cambre back in ballet. Focus can now shift upward towards that top row or judges box to which every instructor wants their students to perform. Care should be taken to not hyper-extend or splay the ribs, and to maintain a long easy neck without additional tension or strain.
This alignment is great for those dramatic, arching gestures we love so much in colorguard. It works beautifully for equipment too, provided that students are reminded to practice it consistently and not default to hyper-extension as they perform.
Again, these are by no means the only "correct" forms of alignment! They are simply the two I have found to be most useful in my colorguard teaching practice. There are plenty of other valid forms, and consideration should be given to student skill levels and somatic awareness, creating a consistent ensemble, and the desired show/movement style.