FOCUS - FOCUS - FOCUS

Poor focusing is one of the most common ways that photographs are ruined. Use the automatic focus of your camera, if you have it; usually, this is done by half-pressing the shutter button. Use the 'macro' mode of your camera for very close-up shots. Don't focus manually unless your auto-focus is having issues; as with metering, automatic focus usually does a far better job of focusing than you can.