Focus stacking is a process where you take a series of identical shots of the subject, and in each successive shot you move the focus slightly. You start focusing at the front or back, and work your way through the subject. Then you load the series into software that combines the in-focus portions of each shot into one shot where everything is in focus. This almost eliminates the depth-of-field issue in macro photography. I used Helicon Focus 4.77 for these shots, but there are many others out there.
Each of the pairs below consists of an outtake from the series that I took, followed by the focus-stacked result.