Create breathing room for your subject.
The best pictures are arguably ones that are simple and have breathing room for the subject. So how do you do that? Try to find the simplest background possible. It’s no different than walking into a super cluttered house versus walking into a clean minimalistic space with very few items to distract you. If you are taking a photo of a person, take the extra second to look around and find a minimal background that doesn’t distract the viewer.