Here are some general guidelines for producing a pleasing background:
- Keep it simple: Avoid busy backgrounds that will distract from the main focus of the photo.
- Avoid having background elements sprouting from your subject.
- Avoid distracting elements: examples are bright spots, spots of clashing color, opposing lines, etc.
- Avoid excessive contrast: a background significantly lighter or darker than your subject can make getting a nice exposure difficult.
These can be accomplished by changing your shooting angle, blurring the background with aperture, moving your subject, make your own background, filling the frame with your subject and post processing among others.