same way i do high jumping - jump left foot raised first... but i kick a ball with my right foot and snowboard left leading, so who knows what's up?
I high jump either way ... both feel comfortable for me, and I kick with either foot, and am a "switchhitter" in baseball, hockey, golf, lacrosse etc. ........... but I mount my bicycle with my right leg up and over first. I can do it the other way, and have done it the other way, but it doesn't feel right.