Make sure your excavated base is sloped to follow the finish grade. Don't create any divits or sunken areas in the excavated area or it will eventually hold ground water and the frost will heave the patio. Also don't forget to excavate beyond the finish perimeter by 12" or so. If you can install a drainpipe at the lower end and have it exit at lower ground then this would benefit.
Oops as I read back and check the area you are in, it looks like frost is not going to be a concern for you.