With the lower water levels on the smallmouth streams, I like to use flies that don't have quite as much weight since I don't need to fight the current to get my flies down. The Murray's Strymph (olive) size 8, Shenk's White Streamer size 6, and Murray's Crayfish size 6 are excellent underwater flies for this time of year. Fish these on a Bright Butt 9ft 2X leader. For topwater I am using the Murray's Chugger (Frog) size 4 or 6 and playing around with the Mr. Rapidan Skater size 8.
Both the North Fork and the South Fork are clear and fishable. The South Fork has been doing better simply because it has more water than the North Fork at this time of year. I am not saying you won't do well on the North Fork, you will just have to work a little harder for it. Wade as carefully as you can so that you are not spooking the bass.
If you need help on access, stop by the fly shop or see my book Virginia Blue Ribbon Streams.
We have a few openings left in our August 24 and Sept 10 Half Day Fly Fishing Lessons. This is a great introduction to fly fishing. We provide the fly rod & reels for the lesson.