Doesn't everyone do it that way? I do like Keith's channel.
Knock sparks downward and hope you don't hit your tin into the mud. Better to hold a bit of char atop the flint to catch the first spark and there it is, in your hand already, so you can put it straight into a bird's nest or use your strong hand to handle the spunk.
His spunk worked, but it's way too large. Period sulfur matches were the size of shoenails and sawn the same way.