Updated: May 27
In a conversation with a wannabe photographer, who wanted to know how to get started with whatever he has. I had only this to say, start with your mobile camera and try to fill your entire frame with a subject. That is one of the techniques.
The subject could be a person's face, a flower etc. Just let it occupy the entire screen on your camera.
Umm... although the above was shot on a macro lens the subject (the Rose) does not fill the frame entirely.
Let us look at another example below
Almost there ... with a clear background the subject stands out with the focal point being the stigma of the flower (the 5 small orange dots at the top)
Let us see another example
Try sprinkling some water on a flower, as it adds to it's beauty and retains some freshness, but the frame is full.
A full frame can also be attained post processing. If you have a red rose as shown in the first picture then crop it so that you just have the subject in the pic. This is a good full frame. Although there is some noise and the quality has faded, the picture can be sharpened (the tool used here is RawTherapee - a free tool) used on a Linux laptop.
There are many cropping tools available on your photo gallery editor on your Android or iPhone too. Just give it a shot
Try your luck in filling the frame and if you still get some background in it ...just crop it.
Cropping sometime can add some tension in the picture. If your photo editor provides some filters, just try it it may be a lot more fun and the picture could look much different and attractive than the original, at times.