Beyond what's already been suggested: Work through the DLI tapes ("tapes"). They're good at throwing varied phrasing at you. For pronunciation in general, fi

Beyond what's already been suggested: Work through the DLI tapes ("tapes"). They're good at throwing varied phrasing at you. For pronunciation in general, find an instructor who's good at teaching Americans how to make the sounds right. There are some mouth positioning tricks that are helpful. http://fsi-dli.yojik.eu/DLI/Chinese%20Mandarin/ http://fsi-dli.yojik.eu/DLI/Chinese%20Mandarin/ for the DLI stuff.