Be familiar with the camera.
Understand the camera's manual and know what each control, switch or menu item does. Each camera is different. Flashes vary and focus depth may be different too. Carry out experiments by taking various shot in different positions. Try shooting using a flash, 2 feet away, or close up. Understand your camera's strengths and limitations and you will be able to choose the best location for a particular shot intuitively.
Take care of lens
Make sure the lens is clear of caps, thumbs or straps. These obstructions can ruin...