I don't really know for sure.....in grade school we did them on paper...and in uni we work with programs that do them for us
theres this program called Kaleidagraph that we use in one of my neuroscience labs for graphing...actually I haven't used it yet but will be in the upcoming weeks....so I can only suggest it because I don't yet know how to use it...my professor says it's better than Excel....?
so dont know if that helps