Some people take and edit photos on their iPhone like a pro, using their iPhone's native Camera app along with all sorts of other apps to produce beautiful images. Others feel majorly accomplished when they can just successfully take and post a photo to Facebook.
But what if you're part of the iPhoneography beginner group and you want to post a photo that isn't sharing ready? For example, a friend recently told me she was about to post a picture of some pretty spring flowers when she realized there was a clump of dog waste in the corner of the image. She didn't know how to crop her photo, so she just deleted it.
For anyone who has ever found him or herself in a similar position, here's how to crop a photo on your iPhone:
Go to Camera Roll and tap on the photo you wish to crop.
Tap Edit in the top right corner.
Tap on the crop icon in the lower right corner. (And don't be afraid to play with the other editing tools!)
Choose Aspect if you want your photo to be a specific size or drag the border of the image until it is the size you want.
Pinch to zoom in on the image and use a finger to drag the image to where you want it in the frame.
Once you have the image as you want it, tap Crop in the upper right corner and then tap Save.
Quick & Dirty Photo Cropping:
If you're not too concerned about image quality, pinch to zoom on your photo until it fills your screen, drag the image until the part you want to capture is where you want it, and then take a screenshot.