Magic wand stopping from selection?

I'm a newb and trying to color a comic. I some times come to pieces of art that are not well connected and I can hand draw finish the line or grab it with lasso or such tools.

What I am wondering is if I can just lasso an area and then magic wand an adjacent to my selection (with add selection on) and grab only whas has already been previously selected without bleeding my new selection through my old selection.

Pretty much, how can I use a selection, to stop magic wand from selecting through it.