Many peoples' photos can be improved by 1) trying to be more still while the HDR photos are being captured, 2) resist the urge to zoom, 3) tap on the area of the photo you want to be in focus before shooting, and 4) generally stick with landscape mode.

This is especially true when taking a picture of someone in front of a mountain (or something similar). Don't zoom! Take a picture of the mountains with the people in view, not a close up picture of the people with a sliver of mountain in the background.