Maybe I should have remained quiet, I thought it was about how you tie the fly onto the leader? Which hand does what?You do something for 58 years and you can't remember how you do it?
I'm sure you tie your flies. Do you use your right hand to tie? Is the vice facing left or right when you face it?
Now I am concentrating...... I hold my hook or fly with my right - then I pass the leader through the eye with leader held in left hand - then I use bout hands as well as my teeth to tie the secret knot that never breaks. The answer is both.
Fly tying my vise points right and I use my right hand more than the left.
You can tell we are near winters end; two popular threads about not telling anyone the place you fish and another up and comer about which hand I hold what with........