?

I have medium brown hair and want to dye it a gingery light auburn colour, like this: http://cl.ly/CdvG

I've heard I should buy a colour two shades lighter than I want the results to be, and that will keep me from having to actually lighten my hair first.

Any tips?

I bought another dye kit of the exact same shade, but idk if I should just dye those spots or do my whole head again.