I will be glad to hear if I am an idiot and there is some standard easy way to do it, but the way I intend to do it when need be is this:
First, make sure Continious Automatic Focus is off. Then,
- Use automatic focus by half pressing the shutter release while the focus subject is in the center of the frame.
- Let go of the shutter release.
- Set to manual focus mode to lock the focus.
- Use automatic exposure by half pressing the shutter release while aiming to the area that needs to be exposed correctly.
- Compose the frame and fully press the (already half pressed) shutter release.
All this just to get the right subject in focus, and the right portion in correct exposure, while letting the camera's proccessor do the job for you. Sounds complicated at first, but is only little so actually.