Sorry, just a short tip this time round…. really busy atm.
I was pm’d about focusing so this is on selecting your AF mode. You will need your camera manual for this one if you don’t know how to change these settings.
Generally when photographing children it is best to use the AI Servo auto focus (I think this is called continous focus for the nikon shooters). In this mode the focus keeps changing with the moving subject while you have your shutter button pressed half way. If you are fortunate enough to have older children or are photographing still life/landscape you could choose One Shot AF but generally I just keep my camera on AI Servo. I only tend to use manual focus when doing macro photography.
Also if your having trouble with focusing, make sure your choose your focal point rather than just using the centre point and recomposing. Look up the selecting AF Point which will be in your Auto Focus section of your manual. Another important aspect of getting good focus is to have a good shutter speed. Usually having a shutter speed of over 125 for short lenses and over 300 for long telephoto lenses. On top of these things it is important to have good exposure.
Sorry so short but hope this is helpful to someone.