The right hand.
In Israel Defense Force, a soldier gives a proper salute by streching his or her arm upwards while forming a straight line towards the right eyebrow (not touching it, just pointing...
I always do when I'm at hockey games or any ceremony where our national anthem is played. When I stand at attention for 'O Canada', I make it a point to put my hand over my heart as I proudly sing...
The hand salute is a sign of respect given with the right hand to show no weapon held against the one you are saluting. As such, it could be rendered by anyone, military or not, as a sign of respect....