Working around iOS' weird image cropping behavior →
If you've ever tried to precisely crop an image in iOS' Photos app (to remove the top status bar and bottom nav bar out of a screenshot, for example) you may have bumped into this issue that Dr. Drang describes. The gist is that doing so using the draggable corners is nearly impossible without unintentionally zooming the image in slightly, messing up the crop. Thankfully there's a solution:
There is a way around this, but it’s also unintuitive, and I often forget about it until my crop is ruined and I have to start over again.
Instead of dragging the crop handles at the corners of the image, touch and drag from the middle of an edge. For God knows what reason, cropping this way doesn’t change the position of the other crop handles. I say this is unintuitive because the handles at the corners look like the things you should be grabbing and moving. There are no visual clues that dragging from the middle of an edge is allowed.
I should have added this to my iOS 11 wish list. The crop mode in the new quick-access UI that appears after you take a screenshot includes little indicators along the edges, but the UI within the Photos app still doesn't make that affordance clear.