How to stand right is the art. This is one of the basics interest of yoga, martial arts or chi kung. It should be great opportunity to practice right standing when recording.
The right position is about finding a balance. We all have imbalances in our bodies, everybody somewhere else. We can find it and balance it. Of course, you are doing this step by step. We're changing details that are tiny. But several of these details together can radically improve the whole. (haha, here is the similarity with post-processing).
If you stand for a long time, I would encourage you to go to ask to yoga or martial art group. The stand itself is very interesting and effective, there is no need to do complicated exercises. If you find the competent teacher, he will be happy to give you instruction for the right stand. You do not have to go to the group often, he'll give you instructions and just come once in a while. Do not be afraid, you are not limited by anything or even your weight. Patience is needed. You can find out how to stand without pain for a very long time.
P.S.:
TheMetalist and Dapsy, I didn't know that you are standing so long. If you have pain, please, be careful.
Ed, great to hear that you can stand for long time.
P.P.S.:
Our yoga teacher told us about Kung fu training in China. Before the Kung fu master begins to teach you, he will let you stand for many, many hours. Then he tries you to kick you in the belly. If you do not move he will accept you for the teaching. This means that you have managed your imbalances in your body and you have stable standing position.