Colour temperature is the first step toward an unexpectedly awesome Instagram post, and matching your color to the conditions of the day will make your photo pop. Did you shoot on a cloudy day, or was it bright and sunny? Cooling down or warming up your color will make your subject show up on screen the way you saw it in person.
Don't just rely on your phone's filters—use your editing tools to really make the shot your own. Play with contrast and saturation, shadows and highlights. Instagram has a host of editing options, and there are a plethora of editing apps out there, too: VSCO, Snapseed, and Adobe Lightroom, for starters.