Every publication and news media has its own style. Even a perfectly written story has to be edited to conform to the publication or media style. By double spacing, you give the editor the space needed to easily work with your copy. Make sure the copy is written in third person. A news story is supposed to be an objective, factual account, and using first or second person implies an unacceptable degree of subjectivity.
Photos are an important commodity to an editor.
Make sure you take the time and allocate the funds to have professional photos available. You cannot expect an editor to know or remember everything about your organization. Make sure you include pertinent bios, fact sheets and, if applicable, product samples.