sitting on your haunches, on your knees, on your butt, in a chair or standing: what physical posture do you most often take during ritual/magickal work and have you noticed a difference in your practice when you do it in a different way?
I stand on my feet. “Here I am!”
I sit to perform divination.
Fifteen years ago I was sitting when I sent an email, at or about 3:30pm.
Al.
For me it’s whatever is most comfortable. So I often fall asleep reclined in bed when I go to perform ritual 
the lesson is, don’t be too comfortable.
Sitting cross-legged or in lotus position with a boomerang pillow under you is good. Standing is good, but I find it inconvenient to do for an entire ritual. Sitting on my knees Japanese style is good too.
I’ve never noticed any difference in outcome. Except if I am too uncomfortable I feel compelled to shuffle around which can break you out of trance. Often just sitting up cross-legged is nice and i often find myself rocking back and forth. Really it’s any position you can be comfortable in for the duration of a ritual.