The Rule of Thirds is a compositional practice where you divide your photo, or viewfinder, into an imaginary nine compartment grid using two vertical lines and two horizontal lines. Following this idea, place your subject in the left or right thirds and leave the other thirds more open. Another approach is to put your subject at the power points where your lines meet. Imagine a fictitious 3×3 grid over every photo you take, as depicted below:
Some cameras/smartphones actually have a rule of thirds grid that superimposes the viewfinder. I suggest turning it on if the option is available until you get used to thinking like this. This way you can create well composed photos:
Jonasson Enigmatic Nirvana 