How to Autofocus In DSLR

1. In manual mode maintain the same difference from the object, as long you shoot the shot
2. Use the and keep changing focus ring to make the subject in focus it needs experience so to get the perfect shot make sure to take multiple shot’s to get the right one.
3. Rack focus - That means you make the subject look blurred to focus, it is highly useful for the entry of the object in the story, and vice versa used for the subject exit from the scene. Make sure it is not used more than two times in the video, It might ruin your project. It's highly useful to introduce your subject.
4. In a good autofocusing camera use the Flexi zone or face detection. For flexion make sure your subject keeps in the middle of the frame so autofocus keep maintains. For the face, detection makes sure that only one object or two subjects can destroy your footage because it makes a problem knowing your camera where to focus.
5. Use the high aperture. It will keep all the frames in focus, but this is mostly used when we have to show the background or landscape. But for the shot where there is no need for landscape, it does not look cinematic.
6. But there is no Hard rule, the rule made for broken. Find out what things works for you by experimenting. As early you got that, as early you level up your storytelling game.