Getting sharp images is most likely your goal. it is not easy sometimes, but with these few tips, it will a lot easier.
The First tip is to use the right focusing mode.
Modern cameras have a variety of different focus modes. Choosing the right focusing mode will help a lot. The normal focusing mode for everyday photography is S-AF, single autofocus. Then the camera will focus when you press the shutter button (or use the back focus button) and the camera will focus. This works best if the subject is not moving.
Use C-AF or AF Tracking for moving subjects.
S-AF will stay on the distance that it was when pressing the shutter button. If your subject is moving it will out of focus. Using C-AF or AF Tracking the camera will follow the subject and try to keep it in focus. This depends on how good your camera is in continuous autofocus and tracking.
Use Face Priority and/or Eye Priority when photographing people.
We usually want to focus on the eye of a person in portraits. Sometimes it can be a bit hard and take our attention away from the model. With Face and Eye priority, we do not need to worry about focusing. We can have our full attention on the model. This will make your photography a lot easier and better. One of the most important things in portraiture is the connection with the photographer and the model.