People think that the only way to take a good picture is to buy a dSLR.... and whilst size does matter in photography it is hardly the be all and end all.
What you decide to put in your photo is universal whether you are using a mobile phone, dSLR or pinhole camera. The nice thing about this is that there are 'rules' we can apply to the content we wish to photograph to make it look the best it possibly can. Keep in mind that all rules are there to be broken ;) and in the simple words of a wise man: "if it's pretty - it's pretty" (Joseph Jean Rolland Dube - or JJRD for any iStockers here)
The Rule of Thirds
This is the mother of all compositional rules - not because it's better than the rest, but it's the one everyone seems to want to follow. There is a good reason for that - this simple rule is very easy to apply and will give you a more powerful image.
The intersecting lines you see on the screen above can be enabled on many cameras today, sometimes referred to as grid lines. These serve as guides on where to position your subject: on the intersection of the lines.
The Rule of thirds is only one of a large number of techniques that can be used. These compositional rules make for a better photo and can help guide your eye when you are composing the shot... and even better, they can be applied to an iPhone or a dSLR
For a really well written guide on compositional rules check out this: Simple guide
And some more examples of the rule of thirds: