Google and try "Back Button Focus" - gives control over when you want the camera to focus, not every time you press the shutter release half way.
Especially useful when shooting birds that return to a perch, e.g. Swallows, Bee-eaters and Kingfishers.
Personally, I use a monopod for macro, helps keep the camera steady while AF-C compensates for me swaying back and forth. Tripods take too long to set up.