Still it’s really useful to be aware of what framing does - a photo that contains some kind of ‘frame within the frame’ is so much stronger than one without.
Let’s look at this famous image of W. Eugene Smith for example - it’s probably one of the best examples to illustrate this visual technique. The trees give the image a second frame, which nicely puts the focus on the two children. Now imagine the photo without the trees, just two children walking away from you. It would be nowhere near as strong.
The frame within the frame leads the eye to the subject, and it fills in the foreground. Filling the image is important, too.
The first image in this post shows the technique in a very slight way, the people at the bottom of the photo kind of give it a border from below. The second photo frames the flowers through the bodies and heads of the ladies around it. Image three blurs the background which gives it a soft border. The next one does the same thing but in the opposite way - the foreground (the two women) is blurred, which puts the focus on what’s behind it. And in the last photo Charlotte’s arms nicely frame the flowers she’s holding.
A lot of the time different techniques will overlap as well - reflections in mirrors for example are also part of the frame within the frame.
Consciously give this technique a go at least once, and you’ll see over time it will happen naturally. :)