Some standing, some kneeling, some prostrate on the ground. Some eyes open, some eyes closed, some blinded by the Glory of the Lord. Some from a lions den, some from the belly of a fish. Some from the depths of a well. Some from a mountain top, some from a valley. Get the point?
Here's a humorous poem that addresses some of the disagreements, and 'ol Cyrus Brown gives pretty good insight in the end. His experience was from a similar place as Jeremiah the Prophet. (well, maybe in a very small way)
Said Deacon Lemuel Keyes,
"And the only proper attitude
Is down upon his knees."
Said Reverend Doctor Wise,
"Is standing straight with outstretched arms
And rapt and upturned eyes."
said Elder Slow,
Such posture is too proud.
"A man should pray with eyes fast-closed
And head contritely bowed."
Austerely clasped in front
With both thumbs pointing toward the ground,"
Said Reverend Doctor Blunt.
Headfirst," said Cyrus Brown,
"With both my heels a-stickin' up
And my head a-pointin' down.
The best prayer I ever said,
The prayingest prayer I ever prayed,
A-standin' on my head."