Find good light. All cameras use light to work -- from the most basic cameras to the most expensive ones. Therefore, finding the best lighting for your photo is going to be the simplest way to get that great photograph. Natural lighting works best and can help capture a clearer, brighter, sharper image. Never take an image directly into a window since the backlight will cause your kiddo to look more like a shadowy figure than their adorable self.
Skip the flash. Most of the time a flash only hinders the picture and you're better off editing the exposure in an app than using the flash to start. If the flash is too strong, it will granulate the picture and flatten the image. Being aware of the light in your surroundings will make it easier to take great pictures of your kids!
Get down to your kids' level. Most adults are taller than their children so it is important to get own to their level to avoid harsh angles. This will help you figure out the composition of your picture, make sure the lighting is great, and communicate with your child to get a fantastic pose!
Use both hands. Shaky hands equal shaky photos! Use both hands and treat your phone as a camera while using it as one. This guarantees you get the clearest photos possible and avoids blurriness caused by too much movement.
Use your grid. Your smart phone has an amazing and easy to use function called the grid. This sections your photo into you guessed it a grid-like pattern that helps you see the composition of your picture. You can use it to center an image and choose focal points.
Tap to focus. Simply tapping your touch screen where you'd like to focus (usually the child's face) enables the smart phone to automatically adjust the exposure for that picture. This helps correct over-exposure and adjusts the lighting to make sure you have a great (and clear!) shot.
Don't use zoom. Using the zoom on your smart phone will cause the pictures to pixelate and become grainy the more you zoom. If you need to get close, try to physically get closer to what you're trying to capture to avoid the pixelation. Or, take a wider photo and crop in an app.
Take multiple pictures. The more the better! By taking multiple shots you heighten your chances of getting a good one. You also might accidentally end up taking better pictures of your child than expected. Delete the bad ones and keep the best two!
Edit with apps. There are a ton of excellent apps you can get to edit pictures on your iPhone before posting, such as Snapseed and Picfx. When editing pictures, it's important to not overuse filters. Most pictures do not need them at all! Slightly adjusting the contrast, brightness, and sharpening the photo, however, can bring out the best in your child and really make them shine!
Play with it! Breaking the rules and playing around with lighting, composition and apps will familiarize yourself with them better and reveal things you hadn't thought of! The best pictures are the ones you love regardless of following the rules -- those that best capture your child in their silly, whimsical, sweet and sometimes frustrating glory.