Back in the old pre-electronic, pre-digital days, I traveled widely with a beautiful 100mm macro lens: manual focus, manual exposure (but in-camera exposure sensing). When time and opportunity permits, and the subject is stable, manually focusing on a tripod mount works fine. (This doesn't work even with slowly moving subjects: you'll find yourself constantly picking up and repositioning the tripod, which becomes just so much dead weight.) For quick photos, moving subjects, or in difficult spots, the trick is to set the focus and simply move the camera forward and back until the subject is in focus. The depth of field often is just a couple millimeters or less, so you have to be precise and steady, but it doesn't take much practice to do it reasonably well. The ability to get a depth-of-field preview is extremely useful here. A good, bright focusing screen is also quite helpful.
I'm sure the fire-a-burst-of-shots technique can help, but I cannot remember any picture (out of thousands) that I lost because of lack of focus and I certainly didn't have any burst capability. That's probably selective memory and age catching up with me, but I don't think I'm that forgetful :-). The vibrations set up by a fast series of shots, coupled with your loss of view in the viewfinder, could actually make the burst technique less reliable then getting off one shot when everything is just right.

This detail from a scanned negative gives a sense of how rapidly the focus blurs with distance: compare the berry stems to the berries themselves. The depth of field is about 3 mm. It was simultaneously focused and composed by moving the camera.