Formal communication is on the wane in modern life, but there are still times when it's the only correct way to reinforce a connection or convey information. If you're applying for a job, looking for a recommendation, or expanding your network, err on the side of formality. Don't let the slightly archaic feel of a formal business letter tempt you into using flowery, outdated language.
Business writing should be clear and concise. Take care, however, that your document does not turn out as an endless series of short, choppy sentences. Keep in mind also that “concise” does not have to mean “blunt”—you still need to think about your tone and the audience for whom you are writing. Consider the following examples: After carefully reviewing this proposal, we have decided to prioritize other projects this quarter.