One thing I have trouble with is shaving the corners of my chin when trying to go from chin down to neck. Any suggestions on fixing this issue, gentlemen?
Concentrate. After that, use a very light touch, and try not to go against the grain until the last pass. Also, I use very short strokes around the chin.
I generally tilt my head upward so that I have a clear sight of my chin counters and can follow them more easily...almost as if tracing it with the razor.
Try using your off hand to apply pressure to stretch the skin behind the stroke, and pull it upward onto the flat of the jawbone. In other words, flatten the corners and shave normally. Any straight razor "how to shave" video demonstrates these techniques, often overlooked and unused by DE shavers.