Conventional wisdom would follow James' advice, with perhaps even more use of manual focus.
I use AF on everything. I've spent upwards of five minutes to get one shot of a creature inside a blowing anemone while in a constant surge using a 105mm with a 2x teleconverter at f/22, effectively at f/45.
Reality is that I can't do better than the cameras AF. I've tried it with the 200mm macro. With strobes extended out to the end of a very long and heavy flat port, keeping the camera steady becomes a real problem.
Using focus lock is an acquired skill and works better for me. Point at the desired focus spot, e.g. eyeball, lock, recompose, fire. This can be easily practiced.
Another technique is to AF on something in the distance range you want to shoot. Flick MSC to manual and reposition camera until you get the target in focus and fire.
Even if you or the subject are moving or bouncing, it is important to AF progessively on your subject. This way refocusing due to a minute distance change is almost instantaneous. Very important with the 105mm which tends to hunt a lot. I often use my hand as a target to get the lens to focus in that range.
Alex says lazy. Maybe I'm lazy, too. But the reality is that as soon as quit messing with camera settings, my composition improved.
1) Turn your SLR into as much a point and shoot as possible, i.e. aperture priority, f/22 and TTL.
2) Identify subject to be captured.
3) Figure out how you want it framed. Angle of subject, negative space, inclusions and exclusions in the scene.
4) Decide your approach based on 3), also look for something to grab to steady yourself.
5) Approach and fire.
6) Vary 3) and fire again.
7) Vary 3) and fire again.
Later I added strobe positioning to 4). Repositioning your strobe(s) on each shot greatly improves the odds of good exposure.
If possible, I really take my time on 4) and 5). Often, when my buddy points something out, I take so long that she thinks I can't see it.
