They write in the present tense. If it is an operation, should pay attention to the sequence of activities. One often uses the passive or passive similar expressions ( "Note" or the impersonal "one"). Especially with item descriptions should pay attention to pertinent adjectives.
A description may be receiver dependent. An amateur is one less jargon expect as a specialist (an expert).
Always write in presence. Words used like "First", "Next" or "Well".