Start by looking closely at what will appear in the photo - its composition. For instance, try to select a simple background that will not be a distraction.
Group shots can look very rigid and too formal, try to organise people so that their faces are at different levels in the image. Consider shooting from above to give a different perspective with everyone looking up at you.
IXUS and PowerShot cameras focus on the area in the centre of your image. Don't worry if your subject is off-centre. Point your camera at them and then press the Shutter Button halfway down until you feel a slight resistance. This locks the focus. Keeping the button depressed, recompose your photo and then press down fully.
More than one shot
Getting a group of people to all look the right way at the same time can be tricky. It makes sense to take plenty of photos. Press the FUNC./SET button and select the "Continuous" Drive Mode or High-speed Burst HQ Mode. As long as you keep the Shutter Button fully depressed, your camera will keep taking photos and, as more are taken, your subjects will relax and look more natural.
Alternatively, select Smart Shutter Mode which will take a number of shots once it detects a wink, smile or a new face in the picture. Learn more about these and other SCN Modes.
After you have taken your photos, a little adjustment with ImageBrowser EX, can enhance what you create. This software came with your camera; check you have the latest version.
For example, if you have used flash, then you might have some unwanted red-eye. Open ImageBrowser EX and select the image. Then click on the "Edit" button and select "Correct Red-eye". You can either let the software correct the red-eye automatically or manually select the area to correct and strength of correction.
Alternatively, if you're sharing the photo directly from the camera, set Red-Eye Correction during shooting or playback.