I might be a little late posting this but it's worth reading anyway. ;-)
Apple realised a series of photography videos yesterday for the iPhone 7, a how to guide if you will. Sixteen videos that covers everything from how to shoot a great portrait to shoot a backlit subject. The videos are all around 30 seconds long and although they are for the iPhone 7 the skills are transferable to most iPhones and other smartphones.
The entire series can be found here, on Apple's website.
Update:
I thought it would be nice to add my favourite video into this post, How to shoot during golden hour on iPhone 7.