I have the very same problems. Our shallow flats are usually less than 8 feet deep way out from the banks. I think that I'm going to start dropping a marker when I'm within 10 to 15 feet on the GPS. Then I think I am going to anchor and cast Sliders or Roadrunners to pinpoint the exact location. Then, finally move up and vertical jig it before leaving.
I know that now we spook a lot of fish off of our brush and stakebeds as we move right up to them to jig fish.