I'm ambi.
What I'm rather pissed off at is any place assuming that you are one or the other. For example, dorms giving you a left-handed desk when your equipment (mouse, keyboard, writing utensils, layout) is all designed for right-handers. The hell guys? I had to deal with that all year. If I'm going to have a left-handed desk, I need the equipment to go with it, or it is annoying as hell to use. Is it that hard to just ask people if they are right handed or left? Same thing with classrooms. Why are there random numbers of left-handed desks? Can we not just ask who is and save someone the trouble that first day of being in a desk they can't write in?
Usually I eat with my left hand and do all my electronic functions with the right, because most things are made for the right to begin with (and have no left-handed counterpart). Furthermore my left eye is not functional so I would be better off leaving that side to simpler tasks. For drawing, it depends on the position I'm in or what I need to draw. Usually I use both hands.
And anything else... well, just a matter of quick thinking. I prefer tossing and throwing with left.