heh...kay so this is what I do for lineart.
its not a very...simple way..i suppose.
nor is it a perfect way, or the only way or the right way, but its how i do and its worked out pretty well so far.
sorry my handwritting is awful DX
and if its hard to see or read
I use Paint tool sai!!!
if you have any quetions, or if i confused you to no end with this, please please please please ask me!! ill do what ever i can to answer any questions and to help you out!!
clean lineart isnt as hard as everyone thinks! ive learned that using multiple layers makes everything SOOO much easier...some people look at using a lot of layers as "cheeting" or some kinda tabu or something like that, personally, i say, if it works, who cares XD
i really hope this helps a bit >_<