I am right handed for writing, every other task is either left or both hands working together.
I had to stop and think about this one though.
Writing = right
Reaching, carrying = left
Petting animal = both - as in I reach out to animal with both my hands, kind of cupped and pet with both my hands, in kind of a smoothing motion, going down from neck to back. (TMI? - sorry)

Also, I have noticed, when hugging someone I tend to "pat" them with the left hand only. My whole family "pats" when hugging but I've never noticed which hand they pat with.
Text/Dial/Calculator buttons = both thumbs together.
DH and DS are right handed entirely.
DD is too small to be writing but reaches, carries and colors with left hand.