I generally do something similar to diagram A, making sure that I get coverage no more than about 3 inches or so apart and that the sides are done to about 1 - 2 inches from the edges. I sort of drag the tip of the glue bottle along the fabric or batting while gently squeezing the bottle. It actually probably looks like a combination of diagrams A and D as sometimes it skips a little here and there.
I also thin my glue a bit. Can't really tell amount of water to glue as I just put some water in until it looks right. LOL I like to glue to be able to run easily, not make large globs, but still stays on top of the fabric and not be so thin that it soaks through like water.
Some of what I just wrote sounds a little vague, but it is a trial and error sort of thing to some degree. I hope I have helped you anyway!