And now, a simple tip for those just starting out with macrophotography. The tip is so simple, actually, that I just gave away the whole game in the title.
Set the camera to manual focus, chose a fixed focus distance, and move the camera back and forth.
The technique of focusing using our bodies rather than the focus ring (or, heaven forbid, the autofocus) works because our tiny subjects are no more than a few centimeters long. A photographer can view the entire world of an insect just by rocking ever so slightly front to back!
Here, the focus ring is relegated to magnification control. Closer focus makes the subject larger, farther focus makes the subject smaller. Set the focus to the desired size of the subject in your final image, and sway your whole body to compose the shot. This physical method of focusing is direct, simple, and intuitive.
So rock on, macrophotographers. Rock on.